webstorm里面关于return返回空值的警告的一个解释

Unnecessary return statements are those which return no value and occur just before the function would have "fallen through" to the bottom. 

这是对第二个return的warn，不能这样用呢，程序如下：

exports.consumeAmountGetReward = function (user,callback) {
    var activity = QActivity.getValidActivity('consumeAmount'),
        config = QSetting.current(),
        localize = config.localize;

    if(!activity){
        callback(localize['20088']);
        return;
    }
    if(user.consumeAmountRemainCount <= 0){
        callback(localize['20076']);
        return;
    }else{
        user.consumeAmountRemainCount -= 1;
        user.consumeAmountCrystal -= activity.data.crystal;
        businese.UserManager.saveUser(user, function (err) {
            if(err){
                callback(err);
            }else{
                callback(null,outputConsumeAmountActivity(user,activity));
            }
        });
    }
};