Fix filterIcon className of Table, close #10937

components/table/filterDropdown.tsx

@@ -174,9 +174,7 @@ export default class FilterMenu<T> extends React.Component<FilterMenuProps<T>, F
 
     return filterIcon ? React.cloneElement(filterIcon as any, {
       title: locale.filterTitle,
-      className: classNames(filterIcon.className, {
-        [`${prefixCls}-icon`]: true,
-      }),
+      className: classNames(`${prefixCls}-icon`, filterIcon.props.className),
     }) : <Icon title={locale.filterTitle} type="filter" className={dropdownSelectedClass} />;
   }
   render() {