minor #18452 [Security] mock the proper method (xabbuh)

This PR was merged into the 2.7 branch.

Discussion
----------

[Security] mock the proper method

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Commits
-------

4b78d03 mock the proper method

Author: Tobion

src/Symfony/Component/Security/Http/Tests/Firewall/SwitchUserListenerTest.php

@@ -187,9 +187,15 @@ public function testExitUserDoesNotDispatchEventWithStringUser()
         $this
             ->request
             ->expects($this->any())
-            ->method('all')
+            ->method('get')
             ->with('_switch_user')
             ->willReturn('_exit');
+        $this
+            ->request
+            ->query
+            ->expects($this->any())
+            ->method('all')
+            ->will($this->returnValue(array()));
         $this
             ->request
             ->expects($this->any())