PCI: replace struct pci_bus secondary/subordinate with busn_res

Replace the struct pci_bus secondary/subordinate members with the
struct resource busn_res.  Later we'll build a resource tree of these
bus numbers.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 447e834..aeda6e9 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -110,7 +110,7 @@
 	struct list_head *tmp;
 	unsigned char max, n;
 
-	max = bus->subordinate;
+	max = bus->busn_res.end;
 	list_for_each(tmp, &bus->children) {
 		n = pci_bus_max_busnr(pci_bus_b(tmp));
 		if(n > max)