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>
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 17a6e46..71c7bea 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -548,8 +548,9 @@
 icmp_ratelimit - INTEGER
 	Limit the maximal rates for sending ICMP packets whose type matches
 	icmp_ratemask (see below) to specific targets.
-	0 to disable any limiting, otherwise the maximal rate in jiffies(1)
-	Default: 100
+	0 to disable any limiting,
+	otherwise the minimal space between responses in milliseconds.
+	Default: 1000
 
 icmp_ratemask - INTEGER
 	Mask made of ICMP types for which rates are being limited.
@@ -1027,8 +1028,9 @@
 icmp/*:
 ratelimit - INTEGER
 	Limit the maximal rates for sending ICMPv6 packets.
-	0 to disable any limiting, otherwise the maximal rate in jiffies(1)
-	Default: 100
+	0 to disable any limiting,
+	otherwise the minimal space between responses in milliseconds.
+	Default: 1000
 
 
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