[PATCH] sk98lin: fix checksumming code

Remove code from sk98lin that does it's own checksum validation.
This code is incorrect when dealing with nested protocols like
VLAN's, and it is better to use regular receive code path to
handle hardware checksum.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>