net/iavf: fix VLAN insertion

[ upstream commit 0d58caa ]

When the driver tells the VF to insert VLAN tag using the L2TAG2 field,
vector Tx path does not use Tx context descriptor and would cause VLAN tag
inserted into the wrong location.

This commit is to fix issue by using normal Tx path to handle L2TAG2 case.

Fixes: 3aa9573 ("net/iavf: fix VLAN insert")

Signed-off-by: Yiding Zhou <yidingx.zhou@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>

drivers/net/iavf/iavf_rxtx_vec_common.h

@@ -250,6 +250,9 @@ iavf_tx_vec_queue_default(struct iavf_tx_queue *txq)
 	if (txq->offloads & IAVF_TX_NO_VECTOR_FLAGS)
 		return -1;
 
+	if (txq->vlan_flag == IAVF_TX_FLAGS_VLAN_TAG_LOC_L2TAG2)
+		return -1;
+
 	if (txq->offloads & IAVF_TX_VECTOR_OFFLOAD)
 		return IAVF_VECTOR_OFFLOAD_PATH;