Fix ThinkPad T42 poweroff failure introduced by by "PM: Introduce pm_power_off_prepare"

Commit bd804eba1c8597cbb7cd5a5f9fe886aae16a079a ("PM: Introduce
pm_power_off_prepare") caused problems in the poweroff path, as reported by
YOSHIFUJI Hideaki / 吉藤英明.

Generally, sysdev_shutdown() should be called after the ACPI preparation for
powering the system off.  To make it happen, we can separate sysdev_shutdown()
from device_shutdown() and call it directly wherever necessary.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/base/power/shutdown.c

@@ -44,7 +44,5 @@ void device_shutdown(void)
 			dev->driver->shutdown(dev);
 		}
 	}
-
-	sysdev_shutdown();
 }
 

include/linux/device.h

@@ -551,6 +551,9 @@ extern void put_device(struct device * dev);
 /* drivers/base/power/shutdown.c */
 extern void device_shutdown(void);
 
+/* drivers/base/sys.c */
+extern void sysdev_shutdown(void);
+
 
 /* drivers/base/firmware.c */
 extern int __must_check firmware_register(struct kset *);

kernel/power/disk.c

@@ -216,6 +216,7 @@ int hibernation_platform_enter(void)
 		 * sleep state after all
 		 */
 		error = hibernation_ops->prepare();
+		sysdev_shutdown();
 		if (!error)
 			error = hibernation_ops->enter();
 	} else {

kernel/sys.c

@@ -804,6 +804,7 @@ static void kernel_restart_prepare(char *cmd)
 	blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
 	system_state = SYSTEM_RESTART;
 	device_shutdown();
+	sysdev_shutdown();
 }
 
 /**
@@ -860,6 +861,7 @@ void kernel_shutdown_prepare(enum system_states state)
 void kernel_halt(void)
 {
 	kernel_shutdown_prepare(SYSTEM_HALT);
+	sysdev_shutdown();
 	printk(KERN_EMERG "System halted.\n");
 	machine_halt();
 }
@@ -876,6 +878,7 @@ void kernel_power_off(void)
 	kernel_shutdown_prepare(SYSTEM_POWER_OFF);
 	if (pm_power_off_prepare)
 		pm_power_off_prepare();
+	sysdev_shutdown();
 	printk(KERN_EMERG "Power down.\n");
 	machine_power_off();
 }