minor #10717 unified return null usages (fabpot)

This PR was merged into the 2.3 branch.

Discussion
----------

unified return null usages

| Q             | A
| ------------- | ---
| License       | MIT

This PR unifies the way we return `null` from a function or method:

 * always use `return;` instead of `return null;` (the current code base uses both);
 * never use `return;` at the end of a function/method.

Commits
-------

d1d569b unified return null usages

3 files changed, 3 insertions, 3 deletions

diff --git a/Core/Authentication/Provider/AnonymousAuthenticationProvider.php b/Core/Authentication/Provider/AnonymousAuthenticationProvider.php
index ea91075..7fbbf85 100644
--- a/Core/Authentication/Provider/AnonymousAuthenticationProvider.php
+++ b/Core/Authentication/Provider/AnonymousAuthenticationProvider.php
@@ -40,7 +40,7 @@ class AnonymousAuthenticationProvider implements AuthenticationProviderInterface
     public function authenticate(TokenInterface $token)
     {
         if (!$this->supports($token)) {
-            return null;
+            return;
         }
 
         if ($this->key !== $token->getKey()) {
diff --git a/Core/Authentication/Provider/PreAuthenticatedAuthenticationProvider.php b/Core/Authentication/Provider/PreAuthenticatedAuthenticationProvider.php
index 3affd78..21ce8d0 100644
--- a/Core/Authentication/Provider/PreAuthenticatedAuthenticationProvider.php
+++ b/Core/Authentication/Provider/PreAuthenticatedAuthenticationProvider.php
@@ -53,7 +53,7 @@ class PreAuthenticatedAuthenticationProvider implements AuthenticationProviderIn
      public function authenticate(TokenInterface $token)
      {
          if (!$this->supports($token)) {
-             return null;
+             return;
          }
 
         if (!$user = $token->getUser()) {
diff --git a/Core/Authentication/Provider/UserAuthenticationProvider.php b/Core/Authentication/Provider/UserAuthenticationProvider.php
index 14fbdda..3728c01 100644
--- a/Core/Authentication/Provider/UserAuthenticationProvider.php
+++ b/Core/Authentication/Provider/UserAuthenticationProvider.php
@@ -58,7 +58,7 @@ abstract class UserAuthenticationProvider implements AuthenticationProviderInter
     public function authenticate(TokenInterface $token)
     {
         if (!$this->supports($token)) {
-            return null;
+            return;
         }
 
         $username = $token->getUsername();