Replace Stream#forEach() with Collection#forEach()

Change-Id: I2b261c3d91d345907b165bd61eb7b6c45011c247
diff --git a/apps/openstacknode/src/main/java/org/onosproject/openstacknode/OpenstackNodeManager.java b/apps/openstacknode/src/main/java/org/onosproject/openstacknode/OpenstackNodeManager.java
index 1bf5858..a5bcaf5 100644
--- a/apps/openstacknode/src/main/java/org/onosproject/openstacknode/OpenstackNodeManager.java
+++ b/apps/openstacknode/src/main/java/org/onosproject/openstacknode/OpenstackNodeManager.java
@@ -663,7 +663,7 @@
             prevNodeMap.remove(node.hostname());
             addOrUpdateNode(node);
         });
-        prevNodeMap.values().stream().forEach(this::deleteNode);
+        prevNodeMap.values().forEach(this::deleteNode);
     }
 
     private class InternalConfigListener implements NetworkConfigListener {