Add support to zero counters conntrack at getting. Currently we can zero all
the conntracks via zero and dump, but it could be useful more fine grain 
zeroing.

Signed-by-off: Pablo Neira Ayuso <pablo@netfilter.org>

Index: net-2.6.git/net/ipv4/netfilter/ip_conntrack_netlink.c
===================================================================
--- net-2.6.git.orig/net/ipv4/netfilter/ip_conntrack_netlink.c	2005-11-04 18:11:06.000000000 +0100
+++ net-2.6.git/net/ipv4/netfilter/ip_conntrack_netlink.c	2005-11-04 18:30:59.000000000 +0100
@@ -788,6 +788,12 @@ ctnetlink_get_conntrack(struct sock *ctn
 
 	err = ctnetlink_fill_info(skb2, NETLINK_CB(skb).pid, nlh->nlmsg_seq, 
 				  IPCTNL_MSG_CT_NEW, 1, ct);
+
+#ifdef CONFIG_IP_NF_CT_ACCT
+	if (NFNL_MSG_TYPE(nlh->nlmsg_type) == IPCTNL_MSG_CT_GET_CTRZERO) 
+		memset(&ct->counters, 0, sizeof(ct->counters));
+#endif
+	
 	ip_conntrack_put(ct);
 	if (err <= 0)
 		goto free;