Issue #3154125 by Patrick R., kevinvhengst: Return type of ContentEnt…

…ityFormInterface::validateForm() seems to be wrong

(cherry picked from commit 74d51c95ee04ee7a4cf671ffe2822fa98e7b1708)

lib/Drupal/Core/Entity/ContentEntityFormInterface.php

@@ -70,7 +70,7 @@ public function isDefaultFormLangcode(FormStateInterface $form_state);
    * For more information about entity validation, see
    * https://www.drupal.org/node/2015613.
    *
-   * @return \Drupal\Core\Entity\ContentEntityTypeInterface
+   * @return \Drupal\Core\Entity\ContentEntityInterface
    *   The built entity.
    */
   public function validateForm(array &$form, FormStateInterface $form_state);