[NET] Can not send icmp netunreach packet

Hi Steven

   There is a bug about icmp netunreach.
   If the kernel does not find a route for a packet, it must send a icmp netunreach packet
   to the source host, and  discard  the packet.
   But the latest kernel  does not send a icmp netunreach packet because of the  fib_lookup
   return value  of -ESRCH when a route  is not found.

   I found a your patch about why changes the "not found" error return for the
   lookup function to -ESRCH. But I think this is not correct.
 
   Your patch is as following:     
  
http://git.kernel.org/?p=linux/kernel/git/davem/net-2.6.git;a=commitdiff;h=83886b6b636173b206f475929e58fac75c6f2446