Updated openstack/openstack
Project: openstack/nova  1fe9c92a33c85c0fffc5b5bc477373bbdd14e71e

libvirt: use instance object for attach_volume

The compute manager uses a instance object here. Add support to the
driver.

Change-Id: I32bc269ce392f1e41f0ddb88b912a5a4bfb7bad8