netfilter: ipv4, defrag: switch hook PFs to nfproto

This patch is a cleanup. Use NFPROTO_* for consistency with other
netfilter code.

Signed-off-by: Alban Crequy <alban.crequy@collabora.co.uk>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Vincent Sanders <vincent.sanders@collabora.co.uk>

net/ipv4/netfilter/nf_defrag_ipv4.c

@@ -94,14 +94,14 @@ static struct nf_hook_ops ipv4_defrag_ops[] = {
 	{
 		.hook		= ipv4_conntrack_defrag,
 		.owner		= THIS_MODULE,
-		.pf		= PF_INET,
+		.pf		= NFPROTO_IPV4,
 		.hooknum	= NF_INET_PRE_ROUTING,
 		.priority	= NF_IP_PRI_CONNTRACK_DEFRAG,
 	},
 	{
 		.hook           = ipv4_conntrack_defrag,
 		.owner          = THIS_MODULE,
-		.pf             = PF_INET,
+		.pf             = NFPROTO_IPV4,
 		.hooknum        = NF_INET_LOCAL_OUT,
 		.priority       = NF_IP_PRI_CONNTRACK_DEFRAG,
 	},