ONOS-7920 - mutex around access to prevent reentrant creation

Change-Id: I9492b2733686e0da4c05f304883f958f92598c79
diff --git a/protocols/netconf/api/src/main/java/org/onosproject/netconf/NetconfDeviceInfo.java b/protocols/netconf/api/src/main/java/org/onosproject/netconf/NetconfDeviceInfo.java
index 930e7a5..3ef4e60 100644
--- a/protocols/netconf/api/src/main/java/org/onosproject/netconf/NetconfDeviceInfo.java
+++ b/protocols/netconf/api/src/main/java/org/onosproject/netconf/NetconfDeviceInfo.java
@@ -295,7 +295,8 @@
      */
     @Override
     public String toString() {
-        return "netconf:" + name + "@" + ipAddress + ":" + port;
+        return "netconf:" + name + "@" + ipAddress + ":" + port +
+            (path.isPresent() ? '/' + path.get() : "");
     }
 
     /**