ipv4: don't remove /proc/net/rt_acct

/proc/net/rt_acct is not created if NET_CLS_ROUTE=n.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/route.c

@@ -586,7 +586,9 @@ static void __net_exit ip_rt_do_proc_exit(struct net *net)
 {
 	remove_proc_entry("rt_cache", net->proc_net_stat);
 	remove_proc_entry("rt_cache", net->proc_net);
+#ifdef CONFIG_NET_CLS_ROUTE
 	remove_proc_entry("rt_acct", net->proc_net);
+#endif
 }
 
 static struct pernet_operations ip_rt_proc_ops __net_initdata =  {