PCI: convert pci_scan_bus() to use pci_create_root_bus()

I plan to deprecate pci_scan_bus_parented(), so use pci_create_root_bus()
directly instead.  pci_scan_bus() itself will be removed as soon as all
callers are gone, so this is just an interim step.

v2: export pci_scan_bus

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 7fc7e14..d09644b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1649,6 +1649,25 @@
 }
 EXPORT_SYMBOL(pci_scan_bus_parented);
 
+struct pci_bus * __devinit pci_scan_bus(int bus, struct pci_ops *ops,
+					void *sysdata)
+{
+	LIST_HEAD(resources);
+	struct pci_bus *b;
+
+	pci_add_resource(&resources, &ioport_resource);
+	pci_add_resource(&resources, &iomem_resource);
+	b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources);
+	if (b) {
+		b->subordinate = pci_scan_child_bus(b);
+		pci_bus_add_devices(b);
+	} else {
+		pci_free_resource_list(&resources);
+	}
+	return b;
+}
+EXPORT_SYMBOL(pci_scan_bus);
+
 #ifdef CONFIG_HOTPLUG
 /**
  * pci_rescan_bus - scan a PCI bus for devices.