When we pull the PPP protocol off the skb, we forgot to update the
hardware RX checksum. This may lead to messages such as
dsl0: hw csum failure.
Similarly, we need to clear the hardware checksum flag when we use
the existing packet to store the decompressed result.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>