fix:更新校验逻辑，优化代码

ruoyi-modules/ruoyi-commodityManagement/src/main/java/org/dromara/commodityManagement/service/impl/BrandServiceImpl.java

@@ -51,9 +51,6 @@ public class BrandServiceImpl implements BrandService {
      */
     @Override
     public int insertBrand(BrandBo brandBo) {
-        if (null != brandMapper.selectVoById(brandBo.getId())){
-            throw new ServiceException("品牌已存在！");
-        }
         Brand brand = MapstructUtils.convert(brandBo, Brand.class);
         validEntityBeforeSave(brand);
         return brandMapper.insert(brand);