[S390] Fix sparse warnings.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index e97f531..8fed360 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -345,7 +345,7 @@
 	if (bdev != bdev->bd_contains)
 		// ro setting is not allowed for partitions
 		return -EINVAL;
-	if (get_user(intval, (int *)argp))
+	if (get_user(intval, (int __user *)argp))
 		return -EFAULT;
 
 	set_disk_ro(bdev->bd_disk, intval);