[gnome-shell] workspace: Update a wrong comment

[Florian Müllner <fmuellner src gnome org>]

commit a7d974481cbb15c067f3c63f215bd030065a72ff
Author: verdre <verdre v0yd nl>
Date:   Wed Jan 30 21:00:56 2019 +0100

    workspace: Update a wrong comment
    
    We showed the app icon there back then, nowadays it's a close button and
    the title of the window.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/346

 js/ui/workspace.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/js/ui/workspace.js b/js/ui/workspace.js
index d8410c2e6..0fa74b670 100644
--- a/js/ui/workspace.js
+++ b/js/ui/workspace.js
@@ -442,7 +442,7 @@ Signals.addSignalMethods(WindowClone.prototype);
 /**
  * @windowClone: Corresponding window clone
  * @parentActor: The actor which will be the parent of all overlay items
- *               such as app icon and window caption
+ *               such as the close button and window caption
  */
 var WindowOverlay = class {
     constructor(windowClone, parentActor) {