Close 'beans' tag in MVC namespace documentation

Issue: SPR-9898
Backport Issue: SPR-9906

Author: philwebb

spring-framework-reference/src/mvc.xml

@@ -4167,7 +4167,7 @@ public class WebConfig {
 
     <mvc:annotation-driven />
 
-&lt;beans&gt;</programlisting>
+&lt;/beans&gt;</programlisting>
 
       <para>The above registers a
       <classname>RequestMappingHandlerMapping</classname>, a