vfs_fruit: let fruit_open_meta() with O_CREAT return a fake-fd

vfs_fruit: let fruit_open_meta() with O_CREAT return a fake-fd

This is the final step in implementing the needed macOS semantics on the
FinderInfo stream: as long as the client hasn't written a non-zero
FinderInfo blob to the stream, there mustn't be a visible filesystem
entry for other openers.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13646

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Thu Nov  1 01:14:23 CET 2018 on sn-devel-144

(cherry picked from commit 1b2de44ea8114cf2025e8b8c843131e2f2dbed27)