netfilter: ipv4: use NFPROTO values for NF_HOOK invocation

The semantic patch that was used:
// <smpl>
@@
@@
(NF_HOOK
|NF_HOOK_COND
|nf_hook
)(
-PF_INET,
+NFPROTO_IPV4,
 ...)
// </smpl>

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

net/ipv4/ipmr.c

@@ -1319,7 +1319,7 @@ static void ipmr_queue_xmit(struct sk_buff *skb, struct mfc_cache *c, int vifi)
 	 * not mrouter) cannot join to more than one interface - it will
 	 * result in receiving multiple packets.
 	 */
-	NF_HOOK(PF_INET, NF_INET_FORWARD, skb, skb->dev, dev,
+	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
 		ipmr_forward_finish);
 	return;