fix namespace

Admin/Admin.php

@@ -26,8 +26,8 @@ use Sonata\AdminBundle\Datagrid\ListMapper;
 use Sonata\AdminBundle\Datagrid\DatagridMapper;
 use Sonata\AdminBundle\Show\ShowMapper;
 
-use Sonata\AdminBundle\Validator\ErrorElement;
-use Sonata\AdminBundle\Validator\Constraints\InlineConstraint;
+use Sonata\CoreBundle\Validator\ErrorElement;
+use Sonata\CoreBundle\Validator\Constraints\InlineConstraint;
 
 use Sonata\AdminBundle\Translator\LabelTranslatorStrategyInterface;
 use Sonata\AdminBundle\Builder\FormContractorInterface;