netfilter: use unsigned variables for packet lengths in ip[6]_queue.

Netlink message lengths can't be negative, so use unsigned variables.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/ipv4/netfilter/ip_queue.c

@@ -402,7 +402,8 @@ ipq_dev_drop(int ifindex)
 static inline void
 __ipq_rcv_skb(struct sk_buff *skb)
 {
-	int status, type, pid, flags, nlmsglen, skblen;
+	int status, type, pid, flags;
+	unsigned int nlmsglen, skblen;
 	struct nlmsghdr *nlh;
 
 	skblen = skb->len;

net/ipv6/netfilter/ip6_queue.c

@@ -403,7 +403,8 @@ ipq_dev_drop(int ifindex)
 static inline void
 __ipq_rcv_skb(struct sk_buff *skb)
 {
-	int status, type, pid, flags, nlmsglen, skblen;
+	int status, type, pid, flags;
+	unsigned int nlmsglen, skblen;
 	struct nlmsghdr *nlh;
 
 	skblen = skb->len;