fixed loading for discussion module

lms/static/coffee/src/discussion/discussion_module.coffee

@@ -18,6 +18,7 @@ if Backbone?
           url = DiscussionUtil.urlFor 'retrieve_discussion', discussion_id
           DiscussionUtil.safeAjax
             $elem: $elem
+            $loading: $elem
             url: url
             type: "GET"
             dataType: 'json'

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

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

lms/static/sass/_discussion.scss

@@ -35,7 +35,13 @@ $tag-text-color: #5b614f;
   }
 }
 
-
+.discussion-loading {
+  background-image: url(../images/discussion/loading.gif);
+  width: 15px;
+  height: 15px;
+  margin-left: 2px;
+  display: inline-block;
+}
 
 /*** Discussions ***/
 
@@ -49,16 +55,6 @@ $tag-text-color: #5b614f;
     margin-top: 0;
   }
 
-  .loading {
-    background-image: url(../images/discussion/loading.gif);
-    width: 15px;
-    height: 15px;
-    margin-left: 2px;
-    display: inline-block;
-  }
-
-
-
   /*** Sidebar ***/
 
   .sidebar-module {