[PATCH] generate hotplug events for cpu online

We already do kobject_hotplug for cpu offline; this adds a kobject_hotplug
call for the online case.  This is being requested by developers of an
application which wants to be notified about both kinds of events.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/base/cpu.c

@@ -44,6 +44,8 @@ static ssize_t store_online(struct sys_device *dev, const char *buf,
 		ret = smp_prepare_cpu(cpu->sysdev.id);
 		if (!ret)
 			ret = cpu_up(cpu->sysdev.id);
+		if (!ret)
+			kobject_hotplug(&dev->kobj, KOBJ_ONLINE);
 		break;
 	default:
 		ret = -EINVAL;