net: lmc: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles

dev_consume_skb_irq() should be called in lmc_interrupt() when skb
xmit done. It makes drop profiles(dropwatch, perf) more friendly.

Delete a redundant comment line in lmc_interrupt().
Signed-off-by: Yang Wei <yang.wei9@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wan/lmc/lmc_main.c

@@ -1320,8 +1320,7 @@ static irqreturn_t lmc_interrupt (int irq, void *dev_instance) /*fold00*/
 			sc->lmc_device->stats.tx_packets++;
                 }
 
-                //                dev_kfree_skb(sc->lmc_txq[i]);
-                dev_kfree_skb_irq(sc->lmc_txq[i]);
+		dev_consume_skb_irq(sc->lmc_txq[i]);
                 sc->lmc_txq[i] = NULL;
 
                 badtx++;