s3:smb2_find: Return that timestamps do not exist as directories

s3:smb2_find: Return that timestamps do not exist as directories

When a Windows client receives a large directory listing while
querying snapshots, it sends a find request asking for the
timestamp as a directory. A Windows server returns NO_SUCH_FILE,
so make sure Samba returns the same. Otherwise the client will
get confused and display timestamps in the 'previous versions' dialog.

Signed-off-by: Christof Schmitt <christof.schmitt@us.ibm.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Tue Sep 10 22:38:51 CEST 2013 on sn-devel-104

(cherry picked from commit c8c0632c871e838fc4465b2a69b4e059e9a126c0)

Fix bug #10137 - shadow_copy2 does not display previous versions correctly over
SMB2.

Autobuild-User(v4-0-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-0-test): Mon Sep 16 11:38:36 CEST 2013 on sn-devel-104