ACPI: dock: fix enum-conversion warning

gcc points out a type mismatch:

drivers/acpi/dock.c: In function 'hot_remove_dock_devices':
drivers/acpi/dock.c:234:53: warning: implicit conversion from 'enum <anonymous>' to 'enum dock_callback_type' [-Wenum-conversion]
234 | dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST, false);

This is harmless because 'false' still has the correct numeric value,
but passing DOCK_CALL_HANDLER documents better what is going on
and avoids the warning.

Fixes: 37f908778f20 ("ACPI / dock: Walk list in reverse order during removal of devices")
Fixes: f09ce741a03a ("ACPI / dock / PCI: Drop ACPI dock notifier chain")
Signed-off-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Hanjun Guo <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/acpi/dock.c

···
 	 * between them).
 	 */
 	list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
-		dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST, false);
+		dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST,
+				   DOCK_CALL_HANDLER);
 
 	list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
 		acpi_bus_trim(dd->adev);