CIFS: Fix wrong restart readdir for SMB1

The existing code calls server->ops->close() that is not
right. This causes XFS test generic/310 to fail. Fix this
by using server->ops->closedir() function.

Cc: <stable@vger.kernel.org> # v3.7+
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
CIFS: Fix wrong filename length for SMB2

The existing code uses the old MAX_NAME constant. This causes
XFS test generic/013 to fail. Fix it by replacing MAX_NAME with
PATH_MAX that SMB1 uses. Also remove an unused MAX_NAME constant
definition.

Cc: <stable@vger.kernel.org> # v3.7+
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Clarify Kconfig help text for CIFS and SMB2/SMB3

Clarify descriptions of SMB2 and SMB3 support in Kconfig

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
resolved the close/closedir conflict