gdataset: drop "key_id" argument from GDataListUpdateAtomicFunc

None of the users actually care about this parameter. And it's unlikely
that they ever will. Also, the passed "key_id" is the argument from
g_datalist_id_update_atomic(). If the caller really cared to know the
"key_id" in the callback, they could pass it as additional user data.

glib/gdataset.c

@@ -1114,7 +1114,7 @@ g_datalist_id_update_atomic (GData **datalist,
       new_destroy = NULL;
     }
 
-  result = callback (key_id, &new_data, &new_destroy, user_data);
+  result = callback (&new_data, &new_destroy, user_data);
 
   if (data && !new_data)
     {

glib/gdatasetprivate.h

@@ -40,7 +40,6 @@ G_BEGIN_DECLS
 
 /*< private >
  * GDataListUpdateAtomicFunc:
- * @key_id: ID of the entry to update
  * @data: (inout) (nullable) (not optional): the existing data corresponding
  *   to @key_id, and return location for the new value for it
  * @destroy_notify: (inout) (nullable) (not optional): the existing destroy
@@ -52,8 +51,7 @@ G_BEGIN_DECLS
  *
  * Since: 2.80
  */
-typedef gpointer (*GDataListUpdateAtomicFunc) (GQuark key_id,
-                                               gpointer *data,
+typedef gpointer (*GDataListUpdateAtomicFunc) (gpointer *data,
                                                GDestroyNotify *destroy_notify,
                                                gpointer user_data);
 

glib/tests/dataset.c

@@ -469,8 +469,7 @@ test_datalist_id_remove_multiple_destroy_order (void)
 }
 
 static gpointer
-_update_atomic_cb (GQuark key_id,
-                   gpointer *data,
+_update_atomic_cb (gpointer *data,
                    GDestroyNotify *destroy_notify,
                    gpointer user_data)
 {

gobject/gobject.c

@@ -367,8 +367,7 @@ weak_ref_data_unlock (WeakRefData *wrdata)
 }
 
 static gpointer
-weak_ref_data_get_or_create_cb (GQuark key_id,
-                                gpointer *data,
+weak_ref_data_get_or_create_cb (gpointer *data,
                                 GDestroyNotify *destroy_notify,
                                 gpointer user_data)
 {