修复 skup 丢失的问题

@@ -141,6 +141,7 @@ Page({
         data = await api.buyerSubmit(skup, channelNo, addressId, () => wx.hideLoading());
       }
       if (data && data.orderCode) {
+        let skup = this.data.skup
         let orderCode = data.orderCode;
         let productId = data.productId ? data.productId : '';
         let params = {