Check for revisionability in the correct way

Closes #3211716

src/Plugin/QueueWorker/UpdateEntityEncryption.php

@@ -69,7 +69,8 @@ class UpdateEntityEncryption extends QueueWorkerBase implements ContainerFactory
   public function processItem($data) {
     $entity_type = $this->entityTypeManager->getDefinition($data['entity_type']);
     $storage = $this->entityTypeManager->getStorage($data['entity_type']);
-    if ($entity_type->isRevisionable()) {
+    $is_revisionable = $entity_type->isRevisionable();
+    if ($is_revisionable) {
       $entity = $storage->loadRevision($data['entity_id']);
     }
     else {
@@ -79,7 +80,8 @@ class UpdateEntityEncryption extends QueueWorkerBase implements ContainerFactory
     if (empty($entity)) {
       return;
     }
-    if ($entity instanceof RevisionableInterface) {
+    // Don't create unnecessary revisions.
+    if ($is_revisionable) {
       $entity->setNewRevision(FALSE);
     }
     $entity->save();