[PATCH] remote memory corruptor in ibmtr.c

ip_summed changes last summer had missed that one.  As the result,
we have ip_summed interpreted as CHECKSUM_PARTIAL now.  IOW,
->csum is interpreted as offset of checksum in the packet.  net/core/*
will both read and modify the value as that offset, with obvious
reasons.  At the very least it's a remote memory corruptor.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>