Fix transfer list item overflow style, close #2674

components/checkbox/style/mixin.less

@@ -173,10 +173,6 @@
     margin-right: 8px;
   }
 
-  .@{checkbox-prefix-cls}-wrapper + span {
-    display: inline-block;
-  }
-
   .@{checkbox-prefix-cls}-group {
     font-size: @font-size-base;
     &-item {

components/transfer/demo/custom-item.md

@@ -6,7 +6,7 @@ title: 自定义渲染行数据
 自定义渲染每一个 Transfer Item，可用于渲染复杂数据。
 
 ````jsx
-import { Transfer, Icon } from 'antd';
+import { Transfer } from 'antd';
 
 const App = React.createClass({
   getInitialState() {
@@ -41,9 +41,9 @@ const App = React.createClass({
   },
   renderItem(item) {
     const customLabel = (
-      <div className="custom-item">
-        {item.title} - {item.description} <Icon type="android" />
-      </div>
+      <span className="custom-item">
+        {item.title} - {item.description}
+      </span>
     );
 
     return {