src: fix function and variable names in comments

The `src/node.js` file is actually loaded and executed by
`node::LoadEnvironment` function.

The variable which has the contents is, `native_node`.

PR-URL: #3039
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

src/node.cc

@@ -2967,7 +2967,7 @@ void LoadEnvironment(Environment* env) {
   env->isolate()->AddMessageListener(OnMessage);
 
   // Compile, execute the src/node.js file. (Which was included as static C
-  // string in node_natives.h. 'natve_node' is the string containing that
+  // string in node_natives.h. 'native_node' is the string containing that
   // source code.)
 
   // The node.js file returns a function 'f'

src/node.js

@@ -1,8 +1,9 @@
 // Hello, and welcome to hacking node.js!
 //
-// This file is invoked by node::Load in src/node.cc, and responsible for
-// bootstrapping the node.js core. Special caution is given to the performance
-// of the startup process, so many dependencies are invoked lazily.
+// This file is invoked by node::LoadEnvironment in src/node.cc, and is
+// responsible for bootstrapping the node.js core. As special caution is given
+// to the performance of the startup process, many dependencies are invoked
+// lazily.
 
 'use strict';