[Bug Report] search cancel button

### Mint UI version
2.2.7

### OS/Browsers version
win10,chorme

### Vue version
2.2.6

### Reproduction Link
[https://jsfiddle.net/pj71jkyw/](https://jsfiddle.net/pj71jkyw/)

### Steps to reproduce
input something，and then click cancel button,there is nothing happen. I read the open source and found out there is no call func (地址一直验证不通过，放在下面了:http://www.loveinwall.com/#/)

### What is Expected?
click the cancle button,and return a call func

### What is actually happening?
there is no call func