fixed bad copied pasted code.

Author: Hugo Hamon

cookbook/security/entity_provider.rst

@@ -242,8 +242,8 @@ The code below shows the implementation of the `UserProviderInterface`_ in the
 
     namespace Acme\Bundle\UserBundle\Entity;
 
-    use namespace Symfony\Component\Security\Core\User\UserInterface;
-    use namespace Symfony\Component\Security\Core\User\UserProviderInterface;
+    use Symfony\Component\Security\Core\User\UserInterface;
+    use Symfony\Component\Security\Core\User\UserProviderInterface;
     use Symfony\Component\Security\Core\Exception\UsernameNotFoundException;
     use Symfony\Component\Security\Core\Exception\UnsupportedUserException;
     use Doctrine\ORM\EntityRepository;