fix:订单退货撤销后，错误提示

cooleshow-mall/mall-admin/src/main/java/com/yonge/cooleshow/admin/service/impl/OmsOrderReturnApplyServiceImpl.java

@@ -77,6 +77,9 @@ public class OmsOrderReturnApplyServiceImpl implements OmsOrderReturnApplyServic
     public int updateStatus(Long id, OmsUpdateStatusParam statusParam) {
         Integer status = statusParam.getStatus();
         OmsOrderReturnApply omsOrderReturnApply = returnApplyMapper.selectByPrimaryKey(id);
+        if (omsOrderReturnApply == null) {
+            throw new BizException("退货订单不存在或被撤销");
+        }
         if (omsOrderReturnApply.getProductPrice().compareTo(statusParam.getReturnAmount()) <0) {
             throw new BizException("退款金额不能大于商品金额");
         }