[NET]: Wrap hard_header_parse

Wrap the hard_header_parse function to simplify next step of
header_ops conversion.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/s390/net/qeth_main.c b/drivers/s390/net/qeth_main.c
index 8c46978..65225b3 100644
--- a/drivers/s390/net/qeth_main.c
+++ b/drivers/s390/net/qeth_main.c
@@ -6561,10 +6561,10 @@
 };
 
 static int
-qeth_hard_header_parse(struct sk_buff *skb, unsigned char *haddr)
+qeth_hard_header_parse(const struct sk_buff *skb, unsigned char *haddr)
 {
-	struct qeth_card *card;
-	struct ethhdr *eth;
+	const struct qeth_card *card;
+	const struct ethhdr *eth;
 
 	card = qeth_get_card_from_dev(skb->dev);
 	if (card->options.layer2)