[gnome-panel] force-quit: avoid deprecated screen functions

[Alberts Muktupāvels <muktupavels src gnome org>]

commit d3eea90f439fb7d3db6bcc8007b8c4f43b93c6c0
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Mar 8 01:08:01 2020 +0200

    force-quit: avoid deprecated screen functions
    
    Using GTK_WIN_POS_CENTER will give better result as GTK will
    center window on monitor not whole screen.

 gnome-panel/panel-force-quit.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)
---
diff --git a/gnome-panel/panel-force-quit.c b/gnome-panel/panel-force-quit.c
index 921f8cb3c..f5b0cf6f4 100644
--- a/gnome-panel/panel-force-quit.c
+++ b/gnome-panel/panel-force-quit.c
@@ -48,10 +48,9 @@ display_popup_window (GdkScreen *screen)
        GtkWidget     *image;
        GtkWidget     *frame;
        GtkWidget     *label;
-       int            screen_width, screen_height;
-       GtkAllocation  allocation;
 
        retval = gtk_window_new (GTK_WINDOW_POPUP);
+       gtk_window_set_position (GTK_WINDOW (retval), GTK_WIN_POS_CENTER);
        atk_object_set_role (gtk_widget_get_accessible (retval), ATK_ROLE_ALERT);
        gtk_window_set_screen (GTK_WINDOW (retval), screen);
        gtk_window_stick (GTK_WINDOW (retval));
@@ -79,17 +78,6 @@ display_popup_window (GdkScreen *screen)
        gtk_box_pack_start (GTK_BOX (vbox), label, FALSE, FALSE, 4);
        gtk_widget_show (label);
 
-       gtk_widget_realize (retval);
-
-       screen_width  = gdk_screen_get_width  (screen);
-       screen_height = gdk_screen_get_height (screen);
-
-       gtk_widget_get_allocation (retval, &allocation);
-
-       gtk_window_move (GTK_WINDOW (retval),
-                        (screen_width  - allocation.width) / 2,
-                        (screen_height - allocation.height) / 2);
-
        gtk_widget_show (GTK_WIDGET (retval));
 
        return retval;