ACPICA: Update names for walk_namespace callbacks to clarify usage.

Use of "preorder" and "postorder" was incorrect. The callbacks are
simply invoked during tree ascent and descent during the
depth-first walk.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/acpica/acnamesp.h b/drivers/acpi/acpica/acnamesp.h
index b83dc32..40b04bd 100644
--- a/drivers/acpi/acpica/acnamesp.h
+++ b/drivers/acpi/acpica/acnamesp.h
@@ -104,8 +104,8 @@
 		       acpi_handle start_object,
 		       u32 max_depth,
 		       u32 flags,
-		       acpi_walk_callback pre_order_visit,
-		       acpi_walk_callback post_order_visit,
+		       acpi_walk_callback descending_callback,
+		       acpi_walk_callback ascending_callback,
 		       void *context, void **return_value);
 
 struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node