man: fix seven cross-references with the wrong section number

Each of these citerefentry targets exists, but is referenced with a
section it is not installed in, so the generated link does not resolve
and 'man <page>' sends the reader to the wrong section.

  systemd-confext              1 -> 8
  systemd-cryptsetup@.service  5 -> 8
  systemd-firstboot.service    8 -> 1  (three places)
  systemd-nspawn               8 -> 1
  systemd-userdbd.service      7 -> 8

The section for each was taken from the refmeta of the page that
defines it. In systemd.special.xml the neighbouring reference to
systemd-veritysetup@.service already uses 8, which is what the
cryptsetup one should have been.

man/kernel-command-line.xml

@@ -648,7 +648,7 @@
 
         <listitem><para>Takes a boolean argument or the special value <literal>headless</literal>, defaults to
         on. If off,
-        <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+        <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>1</manvolnum></citerefentry>
         and
         <citerefentry><refentrytitle>systemd-homed-firstboot.service</refentrytitle><manvolnum>1</manvolnum></citerefentry>
         will not query the user for basic system settings, even if the system boots up for the first time and
@@ -913,7 +913,7 @@
         <member><citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
         <member><citerefentry><refentrytitle>systemd-rfkill.service</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
         <member><citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
-        <member><citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
+        <member><citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
         <member><citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
       </simplelist></para>
   </refsect1>

man/systemd-coredump.xml

@@ -107,7 +107,7 @@
         which ensures that coredumps of a container are attempted to be forwarded to
         <filename>systemd-coredump@.service</filename> running inside the container, i.e the container gets
         to process and store its own core dumps. Note that
-        <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+        <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>
         defaults to this mode if invoked with the <option>--boot</option> switch. This mode of operation is
         generally recommended for security reasons: the security-sensitive processing of the core dump is
         done within the confinements of the container itself, by the container's own code, backed by the

man/systemd-repart.xml

@@ -832,7 +832,7 @@ systemd-repart -C \
 systemd-confext refresh</programlisting>
 
       <para>The DDI generated that way may be applied to the system with
-      <citerefentry><refentrytitle>systemd-confext</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
+      <citerefentry><refentrytitle>systemd-confext</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
     </example>
 
     <example>

man/systemd-vconsole-setup.service.xml

@@ -71,7 +71,7 @@
         credentials.</para>
 
         <para>Note the relationship to the <varname>firstboot.keymap</varname> credential understood by
-        <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>:
+        <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>1</manvolnum></citerefentry>:
         both ultimately affect the same setting, but <varname>firstboot.keymap</varname> is written into
         <filename>/etc/vconsole.conf</filename> on first boot (if not already configured), and then read from
         there by <command>systemd-vconsole-setup</command>, while <varname>vconsole.keymap</varname> is read

man/systemd.special.xml

@@ -1047,7 +1047,7 @@ WantedBy=sleep.target</programlisting>
           <listitem><para>This template unit is used to order mount units and other consumers of block
           devices after services that synthesize these block devices. In particular, this is intended to be
           used with storage services (such as
-          <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>/
+          <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>/
           <citerefentry><refentrytitle>systemd-veritysetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
           that allocate and manage a virtual block device. Storage services are ordered before an instance of
           <filename>blockdev@.target</filename>, and the consumer units after it. The ordering is

man/systemd.system-credentials.xml

@@ -570,7 +570,7 @@
           <filename>/etc/userdb/foobar.group</filename>. Symlinks for the uid/gid will also be created in
           <filename>/etc/userdb/</filename>, as well as the corresponding<filename>.membership</filename>
           files. See
-          <citerefentry><refentrytitle>systemd-userdbd.service</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+          <citerefentry><refentrytitle>systemd-userdbd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
           <citerefentry><refentrytitle>nss-systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>, and
           <citerefentry><refentrytitle>userdbctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
           for details.</para>