net: add fd into listen2 debug info

Add fd into debug message.

PR-URL: https://github.com/iojs/io.js/pull/1442

Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>

lib/net.js

@@ -1128,7 +1128,7 @@ var createServerHandle = exports._createServerHandle =
 
 
 Server.prototype._listen2 = function(address, port, addressType, backlog, fd) {
-  debug('listen2', address, port, addressType, backlog);
+  debug('listen2', address, port, addressType, backlog, fd);
   var self = this;
 
   // If there is not yet a handle, we need to create one and bind.