[gnome-panel] panel-lockdown: avoid deprecated g_type_class_add_private

[Alberts Muktupāvels <muktupavels src gnome org>]

commit d5b783841f3b8d838723e481bef0fe1474b7c43d
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Thu Sep 13 17:30:06 2018 +0300

    panel-lockdown: avoid deprecated g_type_class_add_private

 gnome-panel/panel-lockdown.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)
---
diff --git a/gnome-panel/panel-lockdown.c b/gnome-panel/panel-lockdown.c
index 18bb2c9cd..4bd3915a8 100644
--- a/gnome-panel/panel-lockdown.c
+++ b/gnome-panel/panel-lockdown.c
@@ -53,7 +53,7 @@ enum {
         PROP_DISABLE_FORCE_QUIT
 };
 
-G_DEFINE_TYPE (PanelLockdown, panel_lockdown, G_TYPE_OBJECT);
+G_DEFINE_TYPE_WITH_PRIVATE (PanelLockdown, panel_lockdown, G_TYPE_OBJECT)
 
 static void
 _panel_lockdown_disabled_applets_changed (GSettings     *settings,
@@ -264,9 +264,7 @@ panel_lockdown_dispose (GObject *object)
 static void
 panel_lockdown_init (PanelLockdown *lockdown)
 {
-        lockdown->priv = G_TYPE_INSTANCE_GET_PRIVATE (lockdown,
-                                                      PANEL_TYPE_LOCKDOWN,
-                                                      PanelLockdownPrivate);
+        lockdown->priv = panel_lockdown_get_instance_private (lockdown);
 }
 
 static void
@@ -340,9 +338,6 @@ panel_lockdown_class_init (PanelLockdownClass *lockdown_class)
                         "Whether force quit is disabled or not",
                         TRUE,
                         G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
-
-        g_type_class_add_private (lockdown_class,
-                                  sizeof (PanelLockdownPrivate));
 }
 
 gboolean