Update attach status when instance id invalid.

In cinder.manager do_attach we have a check to make sure the
supplied instance id is a valid UUID which is great, but if it's
not we just raise and dump out, leaving the volume in an attaching
state.

We should update the status to error_attaching in this case and then
raise/return.

Fixes bug: 1192370

Change-Id: Ia759ea7a387544913953ca84e9ed927480c4edfd
Merge "Update attach status when instance id invalid."