Remove dead code.

lodash.js

@@ -397,11 +397,11 @@
    * @private
    * @param {Function} func The function to invoke.
    * @param {*} thisArg The `this` binding of `func`.
-   * @param {...*} [args] The arguments to invoke `func` with.
+   * @param {...*} args The arguments to invoke `func` with.
    * @returns {*} Returns the result of `func`.
    */
   function apply(func, thisArg, args) {
-    var length = args ? args.length : 0;
+    var length = args.length;
     switch (length) {
       case 0: return func.call(thisArg);
       case 1: return func.call(thisArg, args[0]);
@@ -841,7 +841,7 @@
         result = result === undefined ? current : (result + current);
       }
     }
-    return length ? result : 0;
+    return result;
   }
 
   /**