Fix process.assert problem

Introduced in f9f0e5c75c

lib/module.js

@@ -2,6 +2,7 @@ var NativeModule = require('native_module');
 var Script = process.binding('evals').Script;
 var runInThisContext = Script.runInThisContext;
 var runInNewContext = Script.runInNewContext;
+var assert = process.assert;
 
 function Module(id, parent) {
   this.id = id;
@@ -213,7 +214,7 @@ Module.prototype.load = function(filename) {
   debug('load ' + JSON.stringify(filename) +
         ' for module ' + JSON.stringify(this.id));
 
-  process.assert(!this.loaded);
+  assert(!this.loaded);
   this.filename = filename;
 
   var extension = path.extname(filename) || '.js';