tools: move message listener to worker objects

Moving the `message` event listener from the cluster object to each
worker object allows easier backporting of the recent jslint
changes since v5.x and older do not have v6.x's `worker` parameter
in the cluster object's `message` event.

PR-URL: https://github.com/nodejs/node/pull/6212
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>

tools/jslint.js

@@ -125,7 +125,19 @@ if (cluster.isMaster) {
     sendWork(worker);
   });
 
-  cluster.on('message', function(worker, results) {
+  process.on('exit', function() {
+    if (showProgress) {
+      curPath = 'Done';
+      printProgress();
+      outFn('\r\n');
+    }
+    process.exit(failures ? 1 : 0);
+  });
+
+  for (i = 0; i < numCPUs; ++i)
+    cluster.fork().on('message', onWorkerMessage);
+
+  function onWorkerMessage(results) {
     if (typeof results !== 'number') {
       // The worker sent us results that are not all successes
       if (!workerConfig.sendAll)
@@ -136,20 +148,8 @@ if (cluster.isMaster) {
       successes += results;
     }
     // Try to give the worker more work to do
-    sendWork(worker);
-  });
-
-  process.on('exit', function() {
-    if (showProgress) {
-      curPath = 'Done';
-      printProgress();
-      outFn('\r\n');
+    sendWork(this);
   }
-    process.exit(failures ? 1 : 0);
-  });
-
-  for (i = 0; i < numCPUs; ++i)
-    cluster.fork();
 
   function sendWork(worker) {
     if (!files || !files.length) {