Fix phpdoc inconsistencies, simplify no-op sprintf.

(detected by static analysis)

src/Symfony/Bridge/Twig/Extension/WorkflowExtension.php

@@ -85,7 +85,7 @@ class WorkflowExtension extends AbstractExtension
      * Returns marked places.
      *
      * @param object $subject        A subject
-     * @param string $placesNameOnly If true, returns only places name. If false returns the raw representation
+     * @param bool   $placesNameOnly If true, returns only places name. If false returns the raw representation
      * @param string $name           A workflow name
      *
      * @return string[]|int[]

src/Symfony/Component/HttpKernel/Controller/ControllerResolver.php

@@ -219,7 +219,7 @@ class ControllerResolver implements ArgumentResolverInterface, ControllerResolve
         }
 
         if (2 !== count($callable)) {
-            return sprintf('Invalid format for controller, expected array(controller, method) or controller::method.');
+            return 'Invalid format for controller, expected array(controller, method) or controller::method.';
         }
 
         list($controller, $method) = $callable;

src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php

@@ -108,7 +108,7 @@ abstract class AbstractObjectNormalizer extends AbstractNormalizer
      *
      * @return string[]
      */
-    protected function getAttributes($object, $format = null, array $context)
+    protected function getAttributes($object, $format, array $context)
     {
         $class = get_class($object);
         $key = $class.'-'.$context['cache_key'];