PCI: add pci_bus_for_each_resource(), remove direct bus->resource[] refs

No functional change; this converts loops that iterate from 0 to
PCI_BUS_NUM_RESOURCES through pci_bus resource[] table to use the
pci_bus_for_each_resource() iterator instead.

This doesn't change the way resources are stored; it merely removes
dependencies on the fact that they're in a table.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d62a5de..f4a2738 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -386,10 +386,9 @@
 {
 	const struct pci_bus *bus = dev->bus;
 	int i;
-	struct resource *best = NULL;
+	struct resource *best = NULL, *r;
 
-	for(i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
-		struct resource *r = bus->resource[i];
+	pci_bus_for_each_resource(bus, r, i) {
 		if (!r)
 			continue;
 		if (res->start && !(res->start >= r->start && res->end <= r->end))