Add node IP attribute in k8s node class with minor code refactoring

Change-Id: I4c1c86c95acfeb38569b91c1677e4ce8af90460f
diff --git a/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/util/K8sNetworkingUtil.java b/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/util/K8sNetworkingUtil.java
index ebed390..938629f 100644
--- a/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/util/K8sNetworkingUtil.java
+++ b/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/util/K8sNetworkingUtil.java
@@ -400,7 +400,7 @@
         nodeService.completeNodes().forEach(n -> {
             K8sNetwork network = networkService.network(n.hostname());
             if (network != null) {
-                ipMap.put(n.dataIp().toString(), network.gatewayIp().toString());
+                ipMap.put(n.nodeIp().toString(), network.gatewayIp().toString());
             }
         });