icmp: fix units for ratelimit

Convert the sysctl values for icmp ratelimit to use milliseconds instead
of jiffies which is based on kernel configured HZ.
Internal kernel jiffies are not a proper unit for any userspace API.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/icmp.c

@@ -954,7 +954,8 @@ ctl_table ipv6_icmp_table_template[] = {
 		.data		= &init_net.ipv6.sysctl.icmpv6_time,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= &proc_dointvec
+		.proc_handler	= &proc_dointvec_ms_jiffies,
+		.strategy	= &sysctl_ms_jiffies
 	},
 	{ .ctl_name = 0 },
 };