s/fNOP/NOP/, to fix a warning from jshint.

@@ -432,16 +432,16 @@ module.exports = function (grunt) {
 
                     var aArgs   = Array.prototype.slice.call(arguments, 1),
                     fToBind = this,
-                        fNOP    = function() {},
+                        NOP    = function() {},
                         fBound  = function() {
                             return fToBind.apply(this, aArgs.concat(Array.prototype.slice.call(arguments)));
                         };
 
                     if (this.prototype) {
                         // Function.prototype doesn't have a prototype property
-                        fNOP.prototype = this.prototype;
+                        NOP.prototype = this.prototype;
                     }
-                    fBound.prototype = new fNOP();
+                    fBound.prototype = new NOP();
 
                     return fBound;
                 };