[S390] cio: remove registered flag from ccw_device_private

We used to maintain a "registered" flag in our ccw_device_private
structure. This patch removes the "registered" flag and converts
all users of it to device_is_registered which has the exact same
meaning.

Note: The usage the atomic operation test_and_clear_bit is replaced
by the non-atomic if (device_is_registered()) device_del(). This
will not do harm, since we serialize calls to ccw_device_unregister
with a single-threaded workqueue.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/device.c

@@ -303,7 +303,7 @@ int ccw_device_is_orphan(struct ccw_device *cdev)
 
 static void ccw_device_unregister(struct ccw_device *cdev)
 {
-	if (test_and_clear_bit(1, &cdev->private->registered)) {
+	if (device_is_registered(&cdev->dev)) {
 		device_del(&cdev->dev);
 		/* Release reference from device_initialize(). */
 		put_device(&cdev->dev);
@@ -640,12 +640,7 @@ static int ccw_device_register(struct ccw_device *cdev)
 			   cdev->private->dev_id.devno);
 	if (ret)
 		return ret;
-	ret = device_add(dev);
-	if (ret)
-		return ret;
-
-	set_bit(1, &cdev->private->registered);
-	return ret;
+	return device_add(dev);
 }
 
 static int match_dev_id(struct device *dev, void *data)
@@ -669,7 +664,7 @@ static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 {
 	int ret;
 
-	if (test_bit(1, &cdev->private->registered)) {
+	if (device_is_registered(&cdev->dev)) {
 		device_release_driver(&cdev->dev);
 		ret = device_attach(&cdev->dev);
 		WARN_ON(ret == -ENODEV);

drivers/s390/cio/io_sch.h

@@ -145,7 +145,6 @@ struct ccw_device_private {
 	struct subchannel *sch;
 	int state;		/* device state */
 	atomic_t onoff;
-	unsigned long registered;
 	struct ccw_dev_id dev_id;	/* device id */
 	struct subchannel_id schid;	/* subchannel number */
 	struct ccw_request req;		/* internal I/O request */