vfs_fruit: set delete-on-close for empty finderinfo

vfs_fruit: set delete-on-close for empty finderinfo

We previously removed the stream from the underlying filesystem stream
backing store when the client zeroes out FinderInfo in the AFP_AfpInfo
stream, but this causes certain operations to fail (eg stat) when trying
to access the stream over any file-handle open on that stream.

So instead of deleting, set delete-on-close on the stream. The previous
commit already implemented not to list list streams with delete-on-close
set which is necessary to implemenent correct macOS semantics for this
particular stream.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13181

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Ralph Böhme <slow@samba.org>
Autobuild-Date(master): Tue Jan  9 17:09:12 CET 2018 on sn-devel-144

(cherry picked from commit e61e9e98e9ff461055daae2fe78f0202f7ed8663)

Autobuild-User(v4-7-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-7-test): Fri Jan 26 01:29:54 CET 2018 on sn-devel-144