smb: smbdirect: introduce smbdirect_socket_create_{kern,accepting}() and smbdirect_so...

smb: smbdirect: introduce smbdirect_socket_create_{kern,accepting}() and smbdirect_socket_release()

This provides functions which also allocate and free struct
smbdirect_socket.

This allows callers to use the same flow as with
sock_create_kern()/sock_release().

The end goal would be to use sock_create_kern()/sock_release(), but the
first step will be to use smbdirect specific functions without any
struct socket nor struct sock.

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>