PM: Split up sysdev_[suspend|resume] from device_power_[down|up]

Move the sysdev_suspend/resume from the callee to the callers, with
no real change in semantics, so that we can rework the disabling of
interrupts during suspend/hibernation.

This is based on an earlier patch from Linus.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 9b91617..56892a1 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -45,6 +45,13 @@
 		       err);
 		return err;
 	}
+	err = sysdev_suspend(PMSG_SUSPEND);
+	if (err) {
+		printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n",
+			err);
+		device_power_up(PMSG_RESUME);
+		return err;
+	}
 
 	xen_mm_pin_all();
 	gnttab_suspend();
@@ -61,6 +68,7 @@
 	gnttab_resume();
 	xen_mm_unpin_all();
 
+	sysdev_resume();
 	device_power_up(PMSG_RESUME);
 
 	if (!*cancelled) {