virsh returns a list of secret uuids, not keyring names

virsh secret-list outputs a list of secret UUIDs
and whether or not they are used. You would not
find keyring names such as client.volumes or
client.nova in there.

Change-Id: I425187f26018e7c7505fe584ac5cd50a82a32a6b
Merge "virsh returns a list of secret uuids, not keyring names"