ACPI / hotplug / PCI: Drop sun field from struct acpiphp_slot

If the slot unique number is passed as an additional argument to
acpiphp_register_hotplug_slot(), the 'sun' field in struct
acpiphp_slot is only used by ibm_[s|g]et_attention_status(),
but then it's more efficient to store it in struct slot.

Thus move the 'sun' field from struct acpiphp_slot to struct slot
changing its data type to unsigned int in the process, and redefine
acpiphp_register_hotplug_slot() to take the slot number as separate
argument.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index b306e99..a251071 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -352,16 +352,15 @@
 		if (ACPI_FAILURE(status))
 			sun = bridge->nr_slots;
 
-		slot->sun = sun;
 		dbg("found ACPI PCI Hotplug slot %llu at PCI %04x:%02x:%02x\n",
-		    slot->sun, pci_domain_nr(pbus), pbus->number, device);
+		    sun, pci_domain_nr(pbus), pbus->number, device);
 
-		retval = acpiphp_register_hotplug_slot(slot);
+		retval = acpiphp_register_hotplug_slot(slot, sun);
 		if (retval) {
 			bridge->nr_slots--;
 			if (retval == -EBUSY)
 				warn("Slot %llu already registered by another "
-					"hotplug driver\n", slot->sun);
+					"hotplug driver\n", sun);
 			else
 				warn("acpiphp_register_hotplug_slot failed "
 					"(err code = 0x%x)\n", retval);