sfc: use the new __netdev_tx_sent_queue BQL optimisation

As added in 3e59020abf ("net: bql: add __netdev_tx_sent_queue()"), which
 see for performance rationale.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/tx.c

@@ -553,13 +553,10 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)
 	if (!data_mapped && (efx_tx_map_data(tx_queue, skb, segments)))
 		goto err;
 
-	/* Update BQL */
-	netdev_tx_sent_queue(tx_queue->core_txq, skb_len);
-
 	efx_tx_maybe_stop_queue(tx_queue);
 
 	/* Pass off to hardware */
-	if (!xmit_more || netif_xmit_stopped(tx_queue->core_txq)) {
+	if (__netdev_tx_sent_queue(tx_queue->core_txq, skb_len, xmit_more)) {
 		struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);
 
 		/* There could be packets left on the partner queue if those