smb: client: make use of smbdirect_connection_recv_io_refill_work()

smb: client: make use of smbdirect_connection_recv_io_refill_work()

This is basically a copy of smbd_post_send_credits(), but
there are several improvements compared to the existing function:

  We calculate the number of missing posted buffers by getting the
  difference between recv_io.credits.target and recv_io.posted.count.

  Instead of the difference between recv_io.credits.target
  and recv_io.credits.count, because recv_io.credits.count is
  only updated once a message is send to the peer.

  It was not really a problem before, because we have
  a fixed number smbdirect_recv_io buffers, so the
  loop terminated when smbdirect_connection_get_recv_io()
  returns NULL.

  But using recv_io.posted.count makes it easier to
  understand.

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>