ipv4/route: arg delay is useless in rt_cache_flush()

Since route cache deletion (89aef8921bfbac22f), delay is no
more used. Remove it.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index a83d74e..274309d 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -259,7 +259,7 @@
 
 static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
 {
-	rt_cache_flush(ops->fro_net, -1);
+	rt_cache_flush(ops->fro_net);
 }
 
 static const struct fib_rules_ops __net_initdata fib4_rules_ops_template = {