ipv4: convert fib_notify_on_flag_change sysctl to u8

Reduce footprint of sysctls.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/ipv4.h

@@ -191,7 +191,7 @@ struct netns_ipv4 {
 	int sysctl_udp_wmem_min;
 	int sysctl_udp_rmem_min;
 
-	int sysctl_fib_notify_on_flag_change;
+	u8 sysctl_fib_notify_on_flag_change;
 
 #ifdef CONFIG_NET_L3_MASTER_DEV
 	int sysctl_udp_l3mdev_accept;

net/ipv4/sysctl_net_ipv4.c

@@ -1364,9 +1364,9 @@ static struct ctl_table ipv4_net_table[] = {
 	{
 		.procname	= "fib_notify_on_flag_change",
 		.data		= &init_net.ipv4.sysctl_fib_notify_on_flag_change,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(u8),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= proc_dou8vec_minmax,
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= &two,
 	},