vfs_fruit: proper VFS-stackable conversion of FinderInfo

vfs_fruit: proper VFS-stackable conversion of FinderInfo

This fixes the problem that conversion failed with
fruit:metadata=stream. Before we were calling ad_set() which stores the
metadata in the Netatalk compatible format.

Rewrite to fully go through the VFS by calling SMB_VFS_CREATE_FILE() and
SMB_VFS_PWRITE().

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13155

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): Wed Nov 29 08:38:06 CET 2017 on sn-devel-144