Reserve and unreserve volumes
Reserve and unreserve volumes

In order to prevent other cinder users from clobbering volumes that we
have created for kubernetes we reserve volumes before connecting them
and unreserve them after disconnect (before deletion).

Signed-off-by: Adam Litke <ed9d9846a37e30d0259dba27fda9320ea24a6102@redhat.com>

kubernetes/cloud-provider-openstack,kubernetes/cloud-provider-openstack,kubernetes/cloud-provider-openstack