firewire: fw-sbp2: Do ORB timeout right.

When a management ORB times out, either because the fw_transaction
times out or when we don't get the status write, we need to properly
cancel the entire operation.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>