smb: server: fix IRD/ORD negotiation with the client

Already do real negotiation in smb_direct_handle_connect_request()
where we see the requested initiator_depth and responder_resources
from the client.

We should detect legacy iwarp clients using MPA v1
with the custom IRD/ORD negotiation.

We need to send the custom IRD/ORD in big endian,
but we need to try to let clients with broken requests
using little endian (older cifs.ko) to work.

Note the reason why this uses u8 for
initiator_depth and responder_resources is
that the rdma layer also uses it.

Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: linux-rdma@vger.kernel.org
Fixes: 0626e664 ("cifsd: add server handler for central processing and tranport layers")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>