ACPICA: Add post-order callback to acpi_walk_namespace

The existing interface only has a pre-order callback. This change
adds an additional parameter for a post-order callback which will
be more useful for bus scans. ACPICA BZ 779.

Also update the external calls to acpi_walk_namespace.

http://www.acpica.org/bugzilla/show_bug.cgi?id=779

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/pci_slot.c b/drivers/acpi/pci_slot.c
index 45da2ba..11f2197 100644
--- a/drivers/acpi/pci_slot.c
+++ b/drivers/acpi/pci_slot.c
@@ -219,12 +219,12 @@
 
 	dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number);
 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
-				     user_function, &child_context, NULL);
+				     user_function, NULL, &child_context, NULL);
 	if (ACPI_FAILURE(status))
 		goto out;
 
 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
-				     walk_p2p_bridge, &child_context, NULL);
+				     walk_p2p_bridge, NULL, &child_context, NULL);
 out:
 	pci_dev_put(dev);
 	return AE_OK;
@@ -277,12 +277,12 @@
 
 	dbg("root bridge walk, pci_bus = %x\n", pci_bus->number);
 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
-				     user_function, &context, NULL);
+				     user_function, NULL, &context, NULL);
 	if (ACPI_FAILURE(status))
 		return status;
 
 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
-				     walk_p2p_bridge, &context, NULL);
+				     walk_p2p_bridge, NULL, &context, NULL);
 	if (ACPI_FAILURE(status))
 		err("%s: walk_p2p_bridge failure - %d\n", __func__, status);