nfs4_acls: Correctly skip chown when gid did not change

nfs4_acls: Correctly skip chown when gid did not change

Commit 86f7af84 introduced a problem that a chown is always attempted,
even when the owning gid did not change. Then the ACL is set in the file
system as root. Fix the check by correctly comparing with gid, not uid.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15120

Signed-off-by: Christof Schmitt <cs@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
Autobuild-User(master): Christof Schmitt <cs@samba.org>
Autobuild-Date(master): Wed Jul 13 17:30:30 UTC 2022 on sn-devel-184