ret_parameters (and ret_error_id) returned by sd_varlink_call()/
sd_varlink_callbo() are borrowed from the connection, as documented in
sd-varlink.h, and must not be unreffed by the caller. process_hostname()
declared its reply as _cleanup_(sd_json_variant_unrefp), freeing memory
owned by the Varlink connection and leading to a use-after-free/
double-free (the same bug class and ownership mistake just fixed for
pcrextend_pcr_now()/pcrextend_nvpcr_now() in 76a6dc6d).
(cherry picked from commit c556722826c4892939d2a6239ab00d0a343530a8)
venkatchalla06
a77d9ebc58