[ONOS-6235] Implement an interpreter of LispExtensionMappingAddress

Change-Id: I39f66d5e3bcee50b361a6ba33f3fa09e2599f7df
diff --git a/drivers/lisp/src/main/java/org/onosproject/drivers/lisp/extensions/LispNatAddress.java b/drivers/lisp/src/main/java/org/onosproject/drivers/lisp/extensions/LispNatAddress.java
index 1687eb9..e1f2b18 100644
--- a/drivers/lisp/src/main/java/org/onosproject/drivers/lisp/extensions/LispNatAddress.java
+++ b/drivers/lisp/src/main/java/org/onosproject/drivers/lisp/extensions/LispNatAddress.java
@@ -193,7 +193,7 @@
 
     @Override
     public String toString() {
-        return toStringHelper(this)
+        return toStringHelper(type().toString())
                 .add("Map Server UDP port number", msUdpPortNumber)
                 .add("ETR UDP port number", etrUdpPortNumber)
                 .add("global ETR RLOC address", globalEtrRlocAddress)