[cs-fixer] Configure properly the default finder

friendsofphp/php-cs-fixer/2.2/.php_cs.dist

@@ -1,8 +1,14 @@
 <?php
 
+$finder = PhpCsFixer\Finder::create()
+    ->in(__DIR__)
+    ->exclude('var')
+;
+
 return PhpCsFixer\Config::create()
     ->setRules([
         '@Symfony' => true,
         'array_syntax' => ['syntax' => 'short'],
     ])
+    ->setFinder($finder)
 ;