fix deletion of LVM backed instances

    The enumeration of the logical volumes was incorrect,
    thus causing the deletion of instances booted from them,
    to fail.

    Fixes bug: 1078085

Change-Id: Ib899754002cea28f310b042e5d4a7f89416e031e
Cherry-picked: 3c9e48d

nova/virt/libvirt/utils.py

@@ -143,7 +143,7 @@ def list_logical_volumes(vg):
 
     :param vg: volume group name
     """
-    out, err = execute('lvs', '--noheadings', '-o', 'lv_path', vg,
+    out, err = execute('lvs', '--noheadings', '-o', 'lv_name', vg,
                        run_as_root=True)
 
     return [line.strip() for line in out.splitlines()]