Get rid of unused variable warning in drivers/pci/hotplug/pci_hotplug_core.c

Commit 5a7ad7f044941316dc98eda2a087a12a7a50649d removed all uses of
'retval', but didn't remove the variable itself.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/pci/hotplug/pci_hotplug_core.c

@@ -689,8 +689,6 @@ int pci_hp_deregister (struct hotplug_slot *slot)
 int __must_check pci_hp_change_slot_info(struct hotplug_slot *slot,
 					 struct hotplug_slot_info *info)
 {
-	int retval;
-
 	if ((slot == NULL) || (info == NULL))
 		return -ENODEV;