[NETFILTER]: nf_{conntrack,nat}_tftp: annotate TFTP helper with const

Signed-off-by: NJan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/netfilter/nf_nat_tftp.c

@@ -24,7 +24,7 @@ static unsigned int help(struct sk_buff *skb,
 			 enum ip_conntrack_info ctinfo,
 			 struct nf_conntrack_expect *exp)
 {
-	struct nf_conn *ct = exp->master;
+	const struct nf_conn *ct = exp->master;
 
 	exp->saved_proto.udp.port
 		= ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port;

net/netfilter/nf_conntrack_tftp.c

@@ -39,7 +39,8 @@ static int tftp_help(struct sk_buff *skb,
 		     struct nf_conn *ct,
 		     enum ip_conntrack_info ctinfo)
 {
-	struct tftphdr _tftph, *tfh;
+	const struct tftphdr *tfh;
+	struct tftphdr _tftph;
 	struct nf_conntrack_expect *exp;
 	struct nf_conntrack_tuple *tuple;
 	unsigned int ret = NF_ACCEPT;