Fix bug #917615.

Partial Cherry-Pick of 52d58ad.

Changes to nova.compute.manager.recover_live_migration() discarded as they are unnecessary for diablo.

Conflicts:

	nova/compute/manager.py

Change-Id: I773b3f026fd7ebcb2aefcd2ef348cca0c5477238

nova/virt/libvirt/connection.py

@@ -1711,8 +1711,8 @@ def _live_migration(self, ctxt, instance_ref, dest, post_method,
                              FLAGS.live_migration_bandwidth)
 
         except Exception:
-            recover_method(ctxt, instance_ref, dest, block_migration)
-            raise
+            with utils.save_and_reraise_exception():
+                recover_method(ctxt, instance_ref, dest, block_migration)
 
         # Waiting for completion of live_migration.
         timer = utils.LoopingCall(f=None)