Since commit 44e7f029
    util: rewrite auto cleanup macros to use glib's equivalent

VIR_AUTOPTR aliases to g_autoptr. Replace all uses of VIR_DEFINE_AUTOPTR_FUNC
with G_DEFINE_AUTOPTR_CLEANUP_FUNC in preparation for replacing the
rest.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>