Completer fixes for core ONOS CLI commands

Change-Id: Icedfc542ad93a2825b592f3deb6cd96d91779544
diff --git a/cli/src/main/java/org/onosproject/cli/net/McastShowCommand.java b/cli/src/main/java/org/onosproject/cli/net/McastShowCommand.java
index ff9e2e6..3d9b9b5 100644
--- a/cli/src/main/java/org/onosproject/cli/net/McastShowCommand.java
+++ b/cli/src/main/java/org/onosproject/cli/net/McastShowCommand.java
@@ -17,6 +17,7 @@
 
 import org.apache.karaf.shell.api.action.Argument;
 import org.apache.karaf.shell.api.action.Command;
+import org.apache.karaf.shell.api.action.Completion;
 import org.apache.karaf.shell.api.action.lifecycle.Service;
 import org.onlab.packet.IpAddress;
 import org.onosproject.cli.AbstractShellCommand;
@@ -42,6 +43,7 @@
 
     @Argument(index = 0, name = "mcastIp", description = "mcast Ip",
             required = false, multiValued = false)
+    @Completion(McastGroupCompleter.class)
     String mcastIp;
 
     @Override