libmm-glib,3gpp-profile: fix profile comparison logic

Conveniently warned by the compiler...

  ../libmm-glib/mm-3gpp-profile.c: In function ‘mm_3gpp_profile_cmp’:
  ../libmm-glib/mm-3gpp-profile.c:98:1: warning: control reaches end of non-void function [-Wreturn-type]
     98 | }
        | ^

libmm-glib/mm-3gpp-profile.c

@@ -95,6 +95,8 @@ mm_3gpp_profile_cmp (MM3gppProfile         *a,
     if (!(flags & MM_3GPP_PROFILE_CMP_FLAGS_NO_APN_TYPE) &&
         (a->priv->apn_type != b->priv->apn_type))
         return FALSE;
+
+    return TRUE;
 }
 
 /*****************************************************************************/