sh_eth: stop reading ECMR in sh_eth_dev_init()

The code in sh_eth_dev_init()  twiddling the ECMR bits always looked a bit
strange to me:  if one intends to respect 'mdp->duplex', why save old value
of the ECMR.DM bit? As all the other bits are zeroed anyway, we don't really
need to read ECMR before writing to it.
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/sh_eth.c

@@ -1289,7 +1289,6 @@ static int sh_eth_dev_init(struct net_device *ndev, bool start)
 {
 	int ret = 0;
 	struct sh_eth_private *mdp = netdev_priv(ndev);
-	u32 val;
 
 	/* Soft Reset */
 	ret = sh_eth_reset(ndev);
@@ -1342,10 +1341,8 @@ static int sh_eth_dev_init(struct net_device *ndev, bool start)
 	}
 
 	/* PAUSE Prohibition */
-	val = (sh_eth_read(ndev, ECMR) & ECMR_DM) |
-		ECMR_ZPF | (mdp->duplex ? ECMR_DM : 0) | ECMR_TE | ECMR_RE;
-
-	sh_eth_write(ndev, val, ECMR);
+	sh_eth_write(ndev, ECMR_ZPF | (mdp->duplex ? ECMR_DM : 0) |
+		     ECMR_TE | ECMR_RE, ECMR);
 
 	if (mdp->cd->set_rate)
 		mdp->cd->set_rate(ndev);