ACPI / PCI: Make bus registration and unregistration symmetric

Since acpi_pci_slot_enumerate() and acpiphp_enumerate_slots() can get
the ACPI device handle they need from bus->bridge, it is not
necessary to pass that handle to them as an argument.

Drop the second argument of acpi_pci_slot_enumerate() and
acpiphp_enumerate_slots(), rework them to obtain the ACPI handle
from bus->bridge and make acpi_pci_add_bus() and
acpi_pci_remove_bus() entirely symmetrical.

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index dbdc5f7..c78cc43 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -290,24 +290,16 @@
 
 void acpi_pci_add_bus(struct pci_bus *bus)
 {
-	acpi_handle handle = NULL;
-
-	if (bus->bridge)
-		handle = ACPI_HANDLE(bus->bridge);
-	if (acpi_pci_disabled || handle == NULL)
+	if (acpi_pci_disabled || !bus->bridge)
 		return;
 
-	acpi_pci_slot_enumerate(bus, handle);
-	acpiphp_enumerate_slots(bus, handle);
+	acpi_pci_slot_enumerate(bus);
+	acpiphp_enumerate_slots(bus);
 }
 
 void acpi_pci_remove_bus(struct pci_bus *bus)
 {
-	/*
-	 * bus->bridge->acpi_node.handle has already been reset to NULL
-	 * when acpi_pci_remove_bus() is called, so don't check ACPI handle.
-	 */
-	if (acpi_pci_disabled)
+	if (acpi_pci_disabled || !bus->bridge)
 		return;
 
 	acpiphp_remove_slots(bus);