smb: smbdirect: remove unused smbdirect_connection_mr_io_recovery_work()

smb: smbdirect: remove unused smbdirect_connection_mr_io_recovery_work()

This would actually never be used as we only move to
SMBDIRECT_MR_ERROR when we directly call
smbdirect_socket_schedule_cleanup().

Doing an ib_dereg_mr/ib_alloc_mr dance on
working connection is not needed and
it's also pointless on a broken connection
as we don't reuse any ib_pd.

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>