Fix: cosmetic fix for openstack rule sync CLI

Change-Id: I051f5ea7100729ab0aa64544f27c71a9b5d36512
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackSyncRulesCommand.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackSyncRulesCommand.java
index 9ca71a4..1db9704 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackSyncRulesCommand.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackSyncRulesCommand.java
@@ -23,7 +23,6 @@
 import org.onosproject.openstacknode.api.OpenstackNodeAdminService;
 
 import static java.lang.Thread.sleep;
-import static org.onosproject.cli.AbstractShellCommand.get;
 import static org.onosproject.openstacknode.api.NodeState.COMPLETE;
 import static org.onosproject.openstacknode.api.OpenstackNode.NodeType.COMPUTE;
 import static org.onosproject.openstacknode.api.OpenstackNode.NodeType.GATEWAY;
@@ -39,6 +38,9 @@
     private static final long SLEEP_MS = 3000; // we wait 3s for init each node
     private static final long TIMEOUT_MS = 10000; // we wait 10s
 
+    private static final String SUCCESS_MSG = "Successfully synchronize flow rules for node %s!";
+    private static final String FAIL_MSG = "Failed to synchronize flow rules for node %s.";
+
     @Override
     protected void doExecute() {
         // All handlers in this application reacts the node complete event and
@@ -91,9 +93,9 @@
         }
 
         if (result) {
-            print("Successfully synchronize flow rules for node {}!", osNode.hostname());
+            print(SUCCESS_MSG, osNode.hostname());
         } else {
-            error("Failed to synchronize flow rules for node {}.", osNode.hostname());
+            error(FAIL_MSG, osNode.hostname());
         }
     }
 }