Updated openstack/openstack
Project: openstack/nova  62e1ad8056e5e4d67586b6dc56cd00022d10bd9a
null
XenAPI: Speedup get_vhd_parent_uuid

In many cases the VDI record has already been retrieved.
Use it rather than expensively getting a new VDI record from XAPI.

Change-Id: I469e2a415c1f1924010f47d3927ca18c45a7b8f8