[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/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 304caf5..41e0aae 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -302,7 +302,7 @@
 static int zcrypt_open(struct inode *inode, struct file *filp)
 {
 	atomic_inc(&zcrypt_open_count);
-	return 0;
+	return nonseekable_open(inode, filp);
 }
 
 /**