When esp-tx-csum-offload is set to on, the protocol stack shouldn't
calculate the IPsec offload packet's csum, but it does. Because the
callback `.ndo_features_check` incorrectly masked NETIF_F_CSUM_MASK bit.
Fixes: 57f273adbcd4 ("nfp: add framework to support ipsec offloading") Signed-off-by: Huanhuan Wang <huanhuan.wang@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>