ab45015a96
qobject_from_jsonf() aborts on error, unlike qobject_from_jsonv(), which returns null. Since all remaining users of qobject_from_jsonf() cope fine with null, change it to return null. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180703085358.13941-30-armbru@redhat.com>