MDL-46223 Fix frequently used comments in the marking guide

When the frequently used comment contains a character like >, re-use it
directly instead of its HTML entitiy.

grade/grading/form/guide/js/guide.js

@@ -10,7 +10,7 @@ M.gradingform_guide.init = function(Y, options) {
         currentfocus = e.currentTarget;
     });
     Y.all('.markingguidecomment').on('click', function(e) {
-        currentfocus.set('value', currentfocus.get('value') + '\n' + e.currentTarget.get('innerHTML'));
+        currentfocus.set('value', currentfocus.get('value') + '\n' + e.currentTarget.get('text'));
         currentfocus.focus();
     });