emphasis endlabel doesnot work

### Version
5.0.2

### Steps to reproduce
For example:
```js
{
name: '联盟广告',
type: 'line',
stack: '总量',
emphasis: {
focus: 'series',
endLabel: {
show: true,
},
},
data: [220, 182, 191, 234, 290, 330, 310]
},
```
It doesn't work.

### What is expected?
when mouse-over for each line, the line will emphasize and endlabel will display.

### What is actually happening?
only the line emphasize