minor #28441 [Messenger] simple refactoring to have a more readable code (ronfroy)

This PR was squashed before being merged into the 4.2-dev branch (closes #28441).

Discussion
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[Messenger] simple refactoring to have a more readable code

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT
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A simple refactoring to have a more readable code
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Commits
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5f61a27db5 [Messenger] simple refactoring to have a more readable code

Author: nicolas-grekas

Handler/Locator/AbstractHandlerLocator.php

@@ -21,17 +21,8 @@ abstract class AbstractHandlerLocator implements HandlerLocatorInterface
 {
     public function resolve($message): callable
     {
-        $messageClass = \get_class($message);
+        $class = \get_class($message);
 
-        if (null === $handler = $this->resolveFromClass($messageClass)) {
-            throw new NoHandlerForMessageException(sprintf('No handler for message "%s".', $messageClass));
-        }
-
-        return $handler;
-    }
-
-    private function resolveFromClass(string $class): ?callable
-    {
         if ($handler = $this->getHandler($class)) {
             return $handler;
         }
@@ -48,7 +39,7 @@ private function resolveFromClass(string $class): ?callable
             }
         }
 
-        return null;
+        throw new NoHandlerForMessageException(sprintf('No handler for message "%s".', $class));
     }
 
     abstract protected function getHandler(string $class);