Topo2: Bug fixes
1: port lables not showing on mouseover
2: D3 Errors when there are no topology errors and a user pans/zooms

Change-Id: Ic65ba393d23b60673c3a731d1986ee15bbe1bd88
diff --git a/web/gui/src/main/webapp/app/view/topo2/topo2Layout.js b/web/gui/src/main/webapp/app/view/topo2/topo2Layout.js
index 75105ba..c3bfd58 100644
--- a/web/gui/src/main/webapp/app/view/topo2/topo2Layout.js
+++ b/web/gui/src/main/webapp/app/view/topo2/topo2Layout.js
@@ -97,7 +97,7 @@
                       ViewController) {
 
                 var Layout = ViewController.extend({
-                    initialize: function (svg, forceG, uplink, dim, zoomer, opts) {
+                    init: function (svg, forceG, uplink, dim, zoomer, opts) {
                         $log.debug('initialize Layout');
                         instance = this;
 
@@ -371,7 +371,7 @@
                     return instance || new Layout(svg, forceG, uplink, dim, zoomer, opts);
                 }
 
-                return getInstance;
+                return getInstance();
             }
         ]
     );