Fixing Javadoc errors

Change-Id: I72b9d49e052316cbbbef343d367ffffe13cd4e56
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/VirtualNetworkProvider.java b/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/VirtualNetworkProvider.java
index 8e5b19a..bf4a485 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/VirtualNetworkProvider.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/VirtualNetworkProvider.java
@@ -17,6 +17,7 @@
      * @param networkId virtual network identifier
      * @param src       source connection point
      * @param dst       destination connection point
+     * @return new tunnel's id
      */
     TunnelId createTunnel(NetworkId networkId, ConnectPoint src, ConnectPoint dst);