minor #10129 Remove useless $request (ismail1432)

This PR was submitted for the 4.1 branch but it was merged into the 2.8 branch instead (closes #10129).

Discussion
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Remove useless $request

AFAICS the Request class doesn't needs to be injected in the login action, in the example we don't use it.

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Commits
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f22988f Remove useless $request

Author: javiereguiluz

security/form_login_setup.rst

@@ -91,15 +91,14 @@ configuration (``login``):
         // src/AppBundle/Controller/SecurityController.php
 
         // ...
-        use Symfony\Component\HttpFoundation\Request;
         use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
 
         class SecurityController extends Controller
         {
             /**
              * @Route("/login", name="login")
              */
-            public function loginAction(Request $request)
+            public function loginAction()
             {
             }
         }
@@ -142,7 +141,7 @@ Great! Next, add the logic to ``loginAction()`` that displays the login form::
 
     // src/AppBundle/Controller/SecurityController.php
 
-    public function loginAction(Request $request)
+    public function loginAction()
     {
         $authenticationUtils = $this->get('security.authentication_utils');