fix closing tag

Author: josepharhar

source

@@ -61256,7 +61256,7 @@ interface <dfn interface>HTMLDialogElement</dfn> : <span>HTMLElement</span> {
   </ol>
 
   <p>To <dfn data-x="close the dialog">close a dialog</dfn> given a <code>dialog</code> element
-  <var>subject<?var>, a string or null <var>result</var>, and a boolean
+  <var>subject</var>, a string or null <var>result</var>, and a boolean
   <var>ignoreOpenAttribute</var>:</p>
 
   <ol>