problem with arp-request

[Eddie Kohler]

> okay, I remember that in click 1.1 :
> 
> line 36: While configuring `CheckIPHeader at 18 :: CheckIPHeader':
>   warning: IP header unaligned, cannot use fast IP checksum
>   (Try passing the configuration through `click-align'.)
> 
> this was for a raw config written to /proc/click/config
> 
> but click 1.2.0 doesn't give this warning anymore.

It turns out that Linux's checksum functions don't require 4-byte
alignment, so we don't bother generating the warning any more.

I assume that Torsten's problem has nothing to do with alignment since he
is on an x86.

love,
ed