fixed a tiny bug that loading icon sometimes doesn't appear at the right place / doesn't go away

lms/static/coffee/src/discussion/content.coffee

@@ -124,7 +124,7 @@ if Backbone?
         url = @model.urlFor('retrieve')
         DiscussionUtil.safeAjax
           $elem: $elem
-          $loading: $(event.target) if event
+          $loading: @$(".discussion-show-comments")
           type: "GET"
           url: url
           success: (response, textStatus) =>

lms/static/coffee/src/discussion/utils.coffee

 $ ->
   $.fn.extend
     loading: ->
-      $(this).after("<span class='discussion-loading'></span>")
+      @$_loading = $("<span class='discussion-loading'></span>")
+      $(this).after(@$_loading)
     loaded: ->
-      $(this).parent().children(".discussion-loading").remove()
+      @$_loading.remove()
 
 class @DiscussionUtil
 

lms/templates/discussion/mustache/_content.mustache

@@ -7,11 +7,11 @@
     </div>
     <div class="discussion-right-wrapper">
       <ul class="admin-actions">
-        <li><a href="javascript:void(0)" class="admin-endorse">Endorse</a></li>
-        <li><a href="javascript:void(0)" class="admin-edit">Edit</a></li>
-        <li><a href="javascript:void(0)" class="admin-delete">Delete</a></li>
+        <li style="display: none;"><a href="javascript:void(0)" class="admin-endorse">Endorse</a></li>
+        <li style="display: none;"><a href="javascript:void(0)" class="admin-edit">Edit</a></li>
+        <li style="display: none;"><a href="javascript:void(0)" class="admin-delete">Delete</a></li>
         {{#thread}}
-          <li><a href="javascript:void(0)" class="admin-openclose">{{close_thread_text}}</a></li>
+          <li style="display: none;"><a href="javascript:void(0)" class="admin-openclose">{{close_thread_text}}</a></li>
         {{/thread}}
       </ul>
       {{#thread}}