Fix guaranteed NPE in CLI error report

Change-Id: I1340656d09abedf6fb474be62d356eaa04a07ffc
diff --git a/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/cli/OpenstackVtapDeleteCommand.java b/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/cli/OpenstackVtapDeleteCommand.java
index 267d15e..e4a167b 100644
--- a/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/cli/OpenstackVtapDeleteCommand.java
+++ b/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/cli/OpenstackVtapDeleteCommand.java
@@ -40,7 +40,7 @@
         if (vTap != null) {
             print("Removed OpenstackVtap with id { %s }", vTap.id().toString());
         } else {
-            print("Failed to remove OpenstackVtap with id { %s }", vTap.id().toString());
+            print("Failed to remove OpenstackVtap with id { %s }", vTapId);
         }
     }
 }