Use more explicit variable name

Author: VincentLanglet

Kernel/MicroKernelTrait.php

@@ -37,19 +37,19 @@ abstract protected function configureRoutes(RouteCollectionBuilder $routes);
      *
      * You can register extensions:
      *
-     *     $c->loadFromExtension('framework', [
+     *     $container->loadFromExtension('framework', [
      *         'secret' => '%secret%'
      *     ]);
      *
      * Or services:
      *
-     *     $c->register('halloween', 'FooBundle\HalloweenProvider');
+     *     $container->register('halloween', 'FooBundle\HalloweenProvider');
      *
      * Or parameters:
      *
-     *     $c->setParameter('halloween', 'lot of fun');
+     *     $container->setParameter('halloween', 'lot of fun');
      */
-    abstract protected function configureContainer(ContainerBuilder $c, LoaderInterface $loader);
+    abstract protected function configureContainer(ContainerBuilder $container, LoaderInterface $loader);
 
     /**
      * {@inheritdoc}