Fix callbackify test on 0.12

Author: goto-bus-stop

test/node/callbackify.js

@@ -72,7 +72,7 @@ if (typeof Symbol !== 'undefined') {
           assert.strictEqual(err.message, 'Promise was rejected with a falsy value');
           assert.strictEqual(err.reason, value);
         } else {
-          assert.strictEqual(String(value).endsWith(err.message), true);
+          assert.strictEqual(String(value).slice(-err.message.length), err.message);
         }
       } else {
         assert.strictEqual(err, value);
@@ -97,7 +97,7 @@ if (typeof Symbol !== 'undefined') {
           assert.strictEqual(err.message, 'Promise was rejected with a falsy value');
           assert.strictEqual(err.reason, value);
         } else {
-          assert.strictEqual(String(value).endsWith(err.message), true);
+          assert.strictEqual(String(value).slice(-err.message.length), err.message);
         }
       } else {
         assert.strictEqual(err, value);

util.js

@@ -691,8 +691,8 @@ function callbackify(original) {
     // In true node style we process the callback on `nextTick` with all the
     // implications (stack, `uncaughtException`, `async_hooks`)
     original.apply(this, args)
-      .then(function(ret) { process.nextTick(cb, null, ret) },
-            function(rej) { process.nextTick(callbackifyOnRejected, rej, cb) });
+      .then(function(ret) { process.nextTick(cb.bind(null, null, ret)) },
+            function(rej) { process.nextTick(callbackifyOnRejected.bind(null, rej, cb)) });
   }
 
   Object.setPrototypeOf(callbackified, Object.getPrototypeOf(original));