PCI: fix section mismatch warning in pci_scan_child_bus

Fix following warning:
WARNING: vmlinux.o(.text+0x47bdb1): Section mismatch in reference from the function pci_scan_child_bus() to the function .devinit.text:pcibios_fixup_bus()

We had plenty of functions that could be annotated __devinit but due to
the former restriction that exported symbols could not be annotated
they were not so.  So annotate these function and fix the references
from the pci/hotplug/* code to silence the resuting warnings.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index cf22f9e..5e50008 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -1085,7 +1085,7 @@
  * This function should be called per *physical slot*,
  * not per each slot object in ACPI namespace.
  */
-static int enable_device(struct acpiphp_slot *slot)
+static int __ref enable_device(struct acpiphp_slot *slot)
 {
 	struct pci_dev *dev;
 	struct pci_bus *bus = slot->bridge->pci_bus;