dbcheck: store fixed forward link attributes with the correct sorting

The corruption we're trying to fix messed up the sorting,
so there's no point in keeping the current order.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13228

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
