Enable checkstyle trailing spaces rule

Enable the checkstyle rule that detects unneeded trailing spaces
and fix the violations of the rule.

Change-Id: I65567c87142c5a257f0230a55bc4376e770d416f
diff --git a/src/main/java/net/onrc/onos/core/intent/runtime/PlanInstallRuntime.java b/src/main/java/net/onrc/onos/core/intent/runtime/PlanInstallRuntime.java
index 114e718..f6d499b 100644
--- a/src/main/java/net/onrc/onos/core/intent/runtime/PlanInstallRuntime.java
+++ b/src/main/java/net/onrc/onos/core/intent/runtime/PlanInstallRuntime.java
@@ -30,7 +30,7 @@
     IFloodlightProviderService provider;
     private final static Logger log = LoggerFactory.getLogger(PlanInstallRuntime.class);
 
-    public PlanInstallRuntime(//NetworkGraph graph, 
+    public PlanInstallRuntime(//NetworkGraph graph,
                               IFloodlightProviderService provider,
                               IFlowPusherService pusher) {
 //      this.graph = graph;