ipv4: fix error handling in icmp_protocol.

Now we handle icmp errors in each transport protocol's err_handler,
for icmp protocols, that is ping_err. Since this handler only care
of those icmp errors triggered by echo request, errors triggered
by echo reply(which sent by kernel) are sliently ignored.

So wrap ping_err() with icmp_err() to deal with those icmp errors.

Signed-off-by: Li Wei <lw@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/icmp.h b/include/net/icmp.h
index 9ac2524..081439f 100644
--- a/include/net/icmp.h
+++ b/include/net/icmp.h
@@ -41,6 +41,7 @@
 
 extern void	icmp_send(struct sk_buff *skb_in,  int type, int code, __be32 info);
 extern int	icmp_rcv(struct sk_buff *skb);
+extern void	icmp_err(struct sk_buff *, u32 info);
 extern int	icmp_init(void);
 extern void	icmp_out_count(struct net *net, unsigned char type);