CIFS: Fix DFS handling in cifs_get_file_info

We should call cifs_all_info_to_fattr in rc == 0 case only.

Cc: <stable@kernel.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>