This is similar to the previous commit, except this is for a
different type (vahControl) and also fixes the case where _ctl is
passed not initialized to vah_error() (via ctl pointer so that's
probably why compilers don't complain).
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Claudio Fontana <cfontana@suse.de>