net/iavf: fix Tx context descriptor
net/iavf: fix Tx context descriptor

The QW0 of Tx context descriptor should be reset to 0, otherwise the
previous hardware writeback value may pollute the next context descriptor
write.

Fixes: a2b29a7733ef ("net/avf: enable basic Rx Tx")
Cc: stable@dpdk.org

Signed-off-by: Qi Zhang <9e9e58ffa71a29bb7b87766b362515be648fcbe0@intel.com>
Signed-off-by: Beilei Xing <7fb7e49de6d75fb4140bfcdada52e66859d93ebd@intel.com>
Acked-by: Qi Zhang <9e9e58ffa71a29bb7b87766b362515be648fcbe0@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk