[S390] constify function pointer tables.

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/crypto/prng.c b/arch/s390/crypto/prng.c
index 23ed094..0cfefdd 100644
--- a/arch/s390/crypto/prng.c
+++ b/arch/s390/crypto/prng.c
@@ -146,7 +146,7 @@
 	return ret;
 }
 
-static struct file_operations prng_fops = {
+static const struct file_operations prng_fops = {
 	.owner		= THIS_MODULE,
 	.open		= &prng_open,
 	.release	= NULL,