[S390] avoid default_llseek in s390 drivers

Use nonseekable_open for a couple of s390 device drivers. This avoids
the use of default_llseek function which has a dependency on the BKL.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
index 0eabcca..857dfcb 100644
--- a/drivers/s390/char/fs3270.c
+++ b/drivers/s390/char/fs3270.c
@@ -484,6 +484,7 @@
 		raw3270_del_view(&fp->view);
 		goto out;
 	}
+	nonseekable_open(inode, filp);
 	filp->private_data = fp;
 out:
 	mutex_unlock(&fs3270_mutex);