VisualMap 在多个series下设置错误

### Version
5.0.2

### Reproduction link
[https://www.makeapie.com/editor.html?c=xtk0VJl99N&v=1](https://www.makeapie.com/editor.html?c=xtk0VJl99N&v=1)

### Steps to reproduce

```
option = {
legend: {},
tooltip: {},
dataset: {
source: [
['product', '2012', '2013', '2014', '2015'],
['Matcha Latte', 41.1, 30.4, 65.1, 53.3],
['Milk Tea', 86.5, 92.1, 85.7, 83.1],
['Cheese Cocoa', 24.1, 67.2, 79.5, 86.4],
],
},
xAxis: [{ type: 'category' }],
yAxis: [{
gridIndex: 0,
splitNumber: 5,
}],
series: [
{ type: 'bar' },
{ type: 'bar' },
],
visualMap: [
{
type: 'piecewise',
dimension: 2,
outOfRange: { color: '#5470c6' },
pieces: [
{ lt: 40, color: 'yellow' },
],
},
],
};
```

### What is expected?
小于40的柱子颜色为黄色

### What is actually happening?
同series的柱子大于40的也为黄色了