group_audit: Ensure we still log membership changes (with an error) where status...

group_audit: Ensure we still log membership changes (with an error) where status != LDB_SUCCESS

This restores the previous behaviour.  It causes (only) the event ID
to be omitted if status != LDB_SUCCESS or there was a problem getting
the group type.

Errors at this stage are exceedingly rare, because the values have
already been checked by the repl_meta_data module, but this is
cosistent with the rest of the module again.

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Sat Dec 22 01:58:48 CET 2018 on sn-devel-144