net/i40e: fix offload not supported mask

net/i40e: fix offload not supported mask

Just as the name I40E_TX_OFFLOAD_NOTSUP_MASK indicates, it should be the
mask of unsupported features (either not in PKT_TX_OFFLOAD_MASK or in
I40E_TX_OFFLOAD_MASK), however, xor will not get desired result here,
assume bit 0 of PKT_TX_OFFLOAD_MASK and I40E_TX_OFFLOAD_MAKS are 0 which
means corresponding feature is not supported in both sides, then we get
value of bit 0 of I40E_TX_OFFLOAD_NOTSUP_MASK which is 0 via xor, it
implies that it is supported which doesn't meet our expectation.

Correct it by a NOT-AND operation.

Fixes: 3f33e643e5c6 ("net/i40e: add Tx preparation")
Cc: stable@dpdk.org
Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>