CIFS: remove endian related sparse warning

Recent patch had an endian warning ie
cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup()

Signed-off-by: Steve French <smfrench@gmail.com>
CC: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>