smb: client: make use of smbdirect_socket_schedule_cleanup()

smb: client: make use of smbdirect_socket_schedule_cleanup()

This removes smbd_disconnect_rdma_connection() which is basically
the same as smbdirect_socket_schedule_cleanup().
And we pass more useful errors than -ECONNABORTED if we have them.

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>