fixed removeChild bug

Author: ShengxiangChen

cocos2d/base_nodes/CCNode.js

@@ -1026,7 +1026,9 @@ cc.Node = cc.Class.extend(/** @lends cc.Node# */{
      */
     removeFromParent:function (cleanup) {
         if (this._parent) {
-            cleanup = cleanup || true;
+            if (cleanup == null){
+                cleanup = true;
+            }
             this._parent.removeChild(this, cleanup);
         }
     },
@@ -1051,7 +1053,9 @@ cc.Node = cc.Class.extend(/** @lends cc.Node# */{
             return;
         }
 
-        cleanup = cleanup || true;
+        if (cleanup == null){
+            cleanup = true;
+        }
         if (this._children.indexOf(child) > -1) {
             this._detachChild(child, cleanup);
         }