fix typo

app/controllers/v1/learning_objects_controller.rb

@@ -42,7 +42,7 @@ class V1::LearningObjectsController < ApplicationController
   # PATCH/PUT /learning_objects/1.json
   def update
     if @learning_object.update(learning_object_params)
-      learning_object_associations(learning_object)
+      learning_object_associations(@learning_object)
       publisher = LearningObjectPublisher.new(DspaceService.create_client)
       publisher.update_dspace(@learning_object)