vfs_fruit: only veto AppleDouble files with fruit:resource=file

vfs_fruit: only veto AppleDouble files with fruit:resource=file

vfs_fruit only creates AppleDouble files itself when "fruit:resource" is
set to "file" (the default). It is only then the these AppleDouble files
should be treated as an internal representation and should be
inaccessible from clients.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=12526>

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Uri Simchoni <uri@samba.org>