net: name anonymous functions in net module

changing the name proposed to the anonymous function
as stated on #9357 (comment)

Author: pvsousalima

lib/net.js

@@ -1389,7 +1389,7 @@ Server.prototype.listen = function() {
 };
 
 function lookupAndListen(self, port, address, backlog, exclusive) {
-  require('dns').lookup(address, function emitLookup(err, ip, addressType) {
+  require('dns').lookup(address, function doListening(err, ip, addressType) {
     if (err) {
       self.emit('error', err);
     } else {