[libhandy] preferences-group: Remove an unnecessary cast

[Alexander Mikhaylenko <alexm src gnome org>]

commit 665c683a24ab162eb8e5e0d7527b70b3029e9ee7
Author: Matt Turner <mattst88 gmail com>
Date:   Tue Jul 26 12:30:39 2022 -0400

    preferences-group: Remove an unnecessary cast
    
    box is already a `GtkWidget *`, so the cast suggests that there is an
    aliasing violation happening here.

 src/hdy-preferences-group.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/hdy-preferences-group.c b/src/hdy-preferences-group.c
index 366b4791..aee80d81 100644
--- a/src/hdy-preferences-group.c
+++ b/src/hdy-preferences-group.c
@@ -202,7 +202,7 @@ hdy_preferences_group_destroy (GtkWidget *widget)
    * Since we overload forall(), the inherited destroy() won't work as normal.
    * Remove internal widgets ourselves.
    */
-  g_clear_pointer ((GtkWidget **) &priv->box, gtk_widget_destroy);
+  g_clear_pointer (&priv->box, gtk_widget_destroy);
   priv->description = NULL;
   priv->listbox = NULL;
   priv->listbox_box = NULL;