Rename private attribute _element to _el

Change-Id: I9c7a31bd6844636737ffa6456562b997f5e370a3
diff --git a/dev/js/src/hint/menu.js b/dev/js/src/hint/menu.js
index bf1a04b..b7e0d49 100644
--- a/dev/js/src/hint/menu.js
+++ b/dev/js/src/hint/menu.js
@@ -29,7 +29,7 @@
 	          lengthFieldClass : lengthFieldClass
 	        });
       obj._context = context;
-      obj._element.classList.add('hint');
+      obj._el.classList.add('hint');
       obj._hint = hint;
 
       // Make the top item always active