netfilter: nf_conntrack: add nf_ct_kill()

Encapsulate the common

	if (del_timer(&ct->timeout))
		ct->timeout.function((unsigned long)ct)

sequence in a new function.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index c4b1799..79b07c3 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -848,6 +848,13 @@
 }
 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
 
+void nf_ct_kill(struct nf_conn *ct)
+{
+	if (del_timer(&ct->timeout))
+		ct->timeout.function((unsigned long)ct);
+}
+EXPORT_SYMBOL_GPL(nf_ct_kill);
+
 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
 
 #include <linux/netfilter/nfnetlink.h>