net: hns: remove useless variable assignment and comment

The variable head in hns_nic_tx_fini_pro has read a value, but it is
obviously no use. The patch will fix it.
And the comment is nothing to do with the routine, so it has to be removed

Signed-off-by: Qianqian Xie <xieqianqian@huawei.com>
Signed-off-by: Yisen Zhuang <Yisen.Zhuang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns/hns_enet.c

@@ -913,10 +913,7 @@ static int hns_nic_tx_poll_one(struct hns_nic_ring_data *ring_data,
 static void hns_nic_tx_fini_pro(struct hns_nic_ring_data *ring_data)
 {
 	struct hnae_ring *ring = ring_data->ring;
-	int head = ring->next_to_clean;
-
-	/* for hardware bug fixed */
-	head = readl_relaxed(ring->io_base + RCB_REG_HEAD);
+	int head = readl_relaxed(ring->io_base + RCB_REG_HEAD);
 
 	if (head != ring->next_to_clean) {
 		ring_data->ring->q->handle->dev->ops->toggle_ring_irq(