net/sfc: discard last seen VLAN TCI if Tx packet is dropped
net/sfc: discard last seen VLAN TCI if Tx packet is dropped

Early processing of a packet on transmit may change last seen
VLAN TCI in the queue context. If such a packet is eventually
dropped, last seen VLAN TCI must be set to its previous value.

Fixes: 7fd636815a43 ("net/sfc: support VLAN offload on transmit path")
Cc: stable@dpdk.org

Signed-off-by: Ivan Malov <436a2feb05eb79a6862681e66bd0193220e8fb2d@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <ac94ab2a8fe9a9a087f6e24dcbc16626b52c07e8@solarflare.com>

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