[PCI] pci-13: unuse pci_do_scan_bus()

In an attempt to "unuse" pci_do_scan_bus() so it can be eventually
killed, make pci_scan_bus_parented() call the new pci_scan_child_bus()
and pci_bus_add_devices().  The only remaining callers are the
hotplug drivers.

Eventually, pci_bus_add_devices() will be removed from this function -
it is intended that architectures should call this after they have
done any setups and fixups to the scanned bus.

It is legal to call pci_bus_add_devices() on a bus which has already
had this function called, so architectures could update today.

drivers/pci/probe.c

@@ -663,7 +663,8 @@ struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent, int bus,
 	if (b) {
 		b->sysdata = sysdata;
 		b->ops = ops;
-		b->subordinate = pci_do_scan_bus(b);
+		b->subordinate = pci_scan_child_bus(b);
+		pci_bus_add_devices(b);
 	}
 	return b;
 }