Hi:

skbuff: Copy csum instead of csum_start/csum_offset

It's easier to copy the u32 csum instead of its two u16
constituents.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Cheers,
Signed-off-by: NDavid S. Miller <davem@davemloft.net>