Driver core: make device_is_registered() work for class devices

device_is_registered() can use the kobject value for this, so it will
now work with devices that are associated with only a class, not a bus
and a driver.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/device.h b/include/linux/device.h
index d7a1ae0..441461f 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -429,7 +429,6 @@
 	struct kobject kobj;
 	char	bus_id[BUS_ID_SIZE];	/* position on parent bus */
 	struct device_type	*type;
-	unsigned		is_registered:1;
 	unsigned		uevent_suppress:1;
 
 	struct semaphore	sem;	/* semaphore to synchronize calls to
@@ -509,7 +508,7 @@
 
 static inline int device_is_registered(struct device *dev)
 {
-	return dev->is_registered;
+	return dev->kobj.state_in_sysfs;
 }
 
 void driver_init(void);