ACPI: simplify acpi_pci_irq_add_prt() API

A PCI domain cannot change as you descend down subordinate buses, which
makes the 'segment' argument to acpi_pci_irq_add_prt() useless.

Change the interface to take a struct pci_bus *, from whence we can derive
the bus number and segment. Reducing the number of arguments makes life
simpler for callers.

Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/pci_bind.c b/drivers/acpi/pci_bind.c
index 703d2a3..6eb58ef 100644
--- a/drivers/acpi/pci_bind.c
+++ b/drivers/acpi/pci_bind.c
@@ -124,7 +124,7 @@
 {
 	acpi_status status;
 	acpi_handle handle;
-	unsigned char bus;
+	struct pci_bus *bus;
 	struct pci_dev *dev;
 
 	dev = acpi_get_pci_dev(device->handle);
@@ -157,11 +157,11 @@
 		goto out;
 
 	if (dev->subordinate)
-		bus = dev->subordinate->number;
+		bus = dev->subordinate;
 	else
-		bus = dev->bus->number;
+		bus = dev->bus;
 
-	acpi_pci_irq_add_prt(device->handle, pci_domain_nr(dev->bus), bus);
+	acpi_pci_irq_add_prt(device->handle, bus);
 
 out:
 	pci_dev_put(dev);