cifs: remove smb2_send_recv()

Now that we have the plumbing to pass request without an rfc1002
header all the way down to the point we write to the socket we no
longer need the smb2_send_recv() function.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>