[gnome-shell] system: Just use buttonGroup instead of adding extra _actionsItem

[Florian Müllner <fmuellner src gnome org>]

commit 9697c209c0c83e0a07c3f703c18243ee4c57c2fa
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Thu Apr 18 14:24:14 2019 -0500

    system: Just use buttonGroup instead of adding extra _actionsItem
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/499

 js/ui/status/system.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/js/ui/status/system.js b/js/ui/status/system.js
index b7eaef72b..a7aa171cf 100644
--- a/js/ui/status/system.js
+++ b/js/ui/status/system.js
@@ -142,7 +142,7 @@ var Indicator = class extends PanelMenu.SystemIndicator {
                        this._lockScreenAction.visible ||
                        this._altSwitcher.actor.visible);
 
-        this._actionsItem.visible = visible;
+        this.buttonGroup.visible = visible;
     }
 
     _sessionUpdated() {
@@ -302,7 +302,6 @@ var Indicator = class extends PanelMenu.SystemIndicator {
         this._altSwitcher = new AltSwitcher(this._powerOffAction, this._suspendAction);
         item.add(this._altSwitcher.actor, { expand: true, x_fill: false });
 
-        this._actionsItem = item;
         this.menu.addMenuItem(item);