yitume/shop-api: router/api/buy/buy.go; 31 LoC

Found a possible issue in [yitume/shop-api](https://www.github.com/yitume/shop-api) at [router/api/buy/buy.go](https://github.com/yitume/shop-api/blob/41417f0169aad02482d80bf0212c004a14900fae/router/api/buy/buy.go#L278-L308)

Below is the message reported by the analyzer for this snippet of code. Beware that the analyzer only reports the first
issue it finds, so please do not limit your consideration to the contents of the below message.

> reference to value is reassigned at line 283

[Click here to see the code in its original context.](https://github.com/yitume/shop-api/blob/41417f0169aad02482d80bf0212c004a14900fae/router/api/buy/buy.go#L278-L308)

Click here to show the 31 line(s) of Go which triggered the analyzer.

```go
for _, value := range list {
if value.GoodsNum > value.GoodsStock {
err = errors.New("库存不够")
return
}
valuePointer := &value
var cost float64
cost, err = valuePointer.FreightFeeByAddress(addressInfo)
if err != nil {
err = errors.New("数据异常")
return
}

freightWay := valuePointer.GetFreightWay()

freightList = append(freightList, view.Freight{
GoodsSkuId: valuePointer.GoodsSkuId,
FreightFee: cost,
FreightWay: freightWay,
})

if freightWay == "goods_freight_unified" {
// todo 为什么是=
freightUnifiedFee = valuePointer.GoodsFreightFee
} else {
freightTemplateFee += valuePointer.GoodsFreightFee
}

goodsAmount += valuePointer.GoodsPrice * float64(valuePointer.GoodsNum)
goodsNum += valuePointer.GoodsNum
}

```

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See the descriptions of the classifications [here](https://github.com/github-vet/rangeclosure-findings#how-can-i-help) for more information.

commit ID: 41417f0169aad02482d80bf0212c004a14900fae