Correct element click pointer up action's id

The pointer id of pointer up action should be "pointer" to match the pointer move and pointer down actions pointer ids

index.html

@@ -5919,7 +5919,7 @@ <h4><dfn>Element Click</dfn></h4>
 
      <li><p>Let <var>pointer up action</var> be an <a>action
       object</a> constructed with arguments <var>input id</var>,
-      "<code>mouse</code>", and "<code>pointerUp</code>" as arguments.
+      "<code>pointer</code>", and "<code>pointerUp</code>" as arguments.
 
      <li><p><a>Set a property</a> <code>button</code>
       to <code>0</code> on <var>pointer up action</var>.