smb: smbdirect: introduce smbdirect_connection_{get,put}_recv_io()

smb: smbdirect: introduce smbdirect_connection_{get,put}_recv_io()

These are basically copies of {get,put}_receive_buffer() in the client
and they are very similar to {get_free,put}_recvmsg() in the server.

The only difference to {get_free,put}_recvmsg() are the
updating of the sc->statistics.*.

In addition smbdirect_connection_get_recv_io() uses
list_first_entry_or_null() in order to simplify the code.
We also only use it on a healthy connection.

smbdirect_connection_put_recv_io() uses msg->socket instead
of an explicit argument. And it disables any complex_work.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>