drivers/net: Remove CONFIG_WIZNET_TX_FLOW option

This option was there for debugging race conditions,
just remove it, and assume TX_FLOW is always enabled.

Signed-off-by: Mike Sinkovsky <msink@permonline.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/wiznet/w5100.c b/drivers/net/ethernet/wiznet/w5100.c
index c28e1d5..a4079d7 100644
--- a/drivers/net/ethernet/wiznet/w5100.c
+++ b/drivers/net/ethernet/wiznet/w5100.c
@@ -441,8 +441,7 @@
 	struct w5100_priv *priv = netdev_priv(ndev);
 	u16 offset;
 
-	if (IS_ENABLED(CONFIG_WIZNET_TX_FLOW))
-		netif_stop_queue(ndev);
+	netif_stop_queue(ndev);
 
 	offset = w5100_read16(priv, W5100_S0_TX_WR);
 	w5100_writebuf(priv, offset, skb->data, skb->len);
@@ -517,7 +516,7 @@
 	w5100_write(priv, W5100_S0_IR, ir);
 	mmiowb();
 
-	if (IS_ENABLED(CONFIG_WIZNET_TX_FLOW) && (ir & S0_IR_SENDOK)) {
+	if (ir & S0_IR_SENDOK) {
 		netif_dbg(priv, tx_done, ndev, "tx done\n");
 		netif_wake_queue(ndev);
 	}