Fix: resolve CLI auto-completion issue of openstack apps

Change-Id: I0dc973628910cae3588f25e066e81a87a4264f06
diff --git a/apps/openstacknode/app/src/main/java/org/onosproject/openstacknode/cli/OpenstackNodeInitCommand.java b/apps/openstacknode/app/src/main/java/org/onosproject/openstacknode/cli/OpenstackNodeInitCommand.java
index 155ecfc..54e01b5 100644
--- a/apps/openstacknode/app/src/main/java/org/onosproject/openstacknode/cli/OpenstackNodeInitCommand.java
+++ b/apps/openstacknode/app/src/main/java/org/onosproject/openstacknode/cli/OpenstackNodeInitCommand.java
@@ -18,6 +18,7 @@
 
 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.Option;
 import org.apache.karaf.shell.api.action.lifecycle.Service;
 import org.onosproject.cli.AbstractShellCommand;
@@ -45,6 +46,7 @@
 
     @Argument(index = 0, name = "hostnames", description = "Hostname(s) to apply this command",
             required = false, multiValued = true)
+    @Completion(OpenstackHostnameCompleter.class)
     private String[] hostnames = null;
 
     @Override