fix target location for ceilometermiddleware data

this patch corrects I22f929949e3deeb90d14ddad81ccfce9c9de185c.
previous patch incorrectly did not take into account the fact that
ceilometer's api flattens metadata on response.

Change-Id: Iaefd386f7209ee6b8d8c4db5d014aa63cb9f9248
diff --git a/tempest/scenario/test_swift_telemetry_middleware.py b/tempest/scenario/test_swift_telemetry_middleware.py
index 8305641..7466769 100644
--- a/tempest/scenario/test_swift_telemetry_middleware.py
+++ b/tempest/scenario/test_swift_telemetry_middleware.py
@@ -79,15 +79,15 @@
                 meta = sample['resource_metadata']
                 if meta.get('container') and meta['container'] != 'None':
                     containers.append(meta['container'])
-                elif (meta.get('target') and
-                      meta['target']['metadata']['container'] != 'None'):
-                    containers.append(meta['target']['metadata']['container'])
+                elif (meta.get('target.metadata:container') and
+                      meta['target.metadata:container'] != 'None'):
+                    containers.append(meta['target.metadata:container'])
 
                 if meta.get('object') and meta['object'] != 'None':
                     objects.append(meta['object'])
-                elif (meta.get('target') and
-                      meta['target']['metadata']['object'] != 'None'):
-                    objects.append(meta['target']['metadata']['object'])
+                elif (meta.get('target.metadata:object') and
+                      meta['target.metadata:object'] != 'None'):
+                    objects.append(meta['target.metadata:object'])
 
             return (container_name in containers and obj_name in objects)