nbd: replace sysfs_create_file() with device_create_file()

Signed-off-by: NWANG Cong <amwang@redhat.com>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

drivers/block/nbd.c

@@ -406,9 +406,9 @@ static int nbd_do_it(struct nbd_device *lo)
 	BUG_ON(lo->magic != LO_MAGIC);
 
 	lo->pid = task_pid_nr(current);
-	ret = sysfs_create_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr);
+	ret = device_create_file(disk_to_dev(lo->disk), &pid_attr);
 	if (ret) {
-		printk(KERN_ERR "nbd: sysfs_create_file failed!");
+		printk(KERN_ERR "nbd: device_create_file failed!");
 		lo->pid = 0;
 		return ret;
 	}
@@ -416,7 +416,7 @@ static int nbd_do_it(struct nbd_device *lo)
 	while ((req = nbd_read_stat(lo)) != NULL)
 		nbd_end_request(req);
 
-	sysfs_remove_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr);
+	device_remove_file(disk_to_dev(lo->disk), &pid_attr);
 	lo->pid = 0;
 	return 0;
 }