PCI: annotate pci_rescan_bus as __ref, not __devinit

pci_rescan_bus was annotated as __devinit, which is wrong,
because it will never be part of device initialization.
Howevever, we can't simply drop the annotation, because then we
get section warnings about calling pci_scan_child_bus (which is
correctly marked as __devinit).

pci_rescan_bus will only get built when CONFIG_HOTPLUG is set,
meaning that __devinit is a nop, so we know that pci_scan_child_bus
has not been freed.

Annotate as __ref to silence modpost.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/probe.c

@@ -1220,7 +1220,7 @@ EXPORT_SYMBOL(pci_scan_bus_parented);
  *
  * Returns the max number of subordinate bus discovered.
  */
-unsigned int __devinit pci_rescan_bus(struct pci_bus *bus)
+unsigned int __ref pci_rescan_bus(struct pci_bus *bus)
 {
 	unsigned int max;
 	struct pci_dev *dev;