PCI Hotplug: fix __must_check warnings

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/pci/hotplug/pci_hotplug.h b/drivers/pci/hotplug/pci_hotplug.h
index e929b7c..772523d 100644
--- a/drivers/pci/hotplug/pci_hotplug.h
+++ b/drivers/pci/hotplug/pci_hotplug.h
@@ -172,8 +172,8 @@
 
 extern int pci_hp_register		(struct hotplug_slot *slot);
 extern int pci_hp_deregister		(struct hotplug_slot *slot);
-extern int pci_hp_change_slot_info	(struct hotplug_slot *slot,
-					 struct hotplug_slot_info *info);
+extern int __must_check pci_hp_change_slot_info	(struct hotplug_slot *slot,
+						 struct hotplug_slot_info *info);
 extern struct subsystem pci_hotplug_slots_subsys;
 
 /* PCI Setting Record (Type 0) */