AMBARI-13945. Missing HDFS tag.HAState JMX Metric Causes JavaScript Errors (akovalenko)

ambari-web/app/mappers/service_metrics_mapper.js

@@ -402,14 +402,8 @@ App.serviceMetricsMapper = App.QuickDataMapper.create({
       if (this.isHostComponentPresent(component, 'NAMENODE')) {
         //enabled HA
         if (component.host_components.length == 2) {
-          var haState1;
-          var haState2;
-          if (component.host_components[1].metrics && component.host_components[1].metrics.dfs) {
-            haState2 = component.host_components[1].metrics.dfs.FSNamesystem.HAState;
-          }
-          if (component.host_components[0].metrics && component.host_components[0].metrics.dfs) {
-            haState1 = component.host_components[0].metrics.dfs.FSNamesystem.HAState;
-          }
+          var haState1 = Em.get(component.host_components[0], 'metrics.dfs.FSNamesystem.HAState');
+          var haState2 = Em.get(component.host_components[1], 'metrics.dfs.FSNamesystem.HAState');
           var active_name_node = [];
           var standby_name_nodes = [];
           switch (haState1) {