sh_eth: use ETH_ZLEN instead of home-grown #define

The driver #define's and uses ETHERSMALL macro for the minimum Ethernet frame
size for which we have a standard macro ETH_ZLEN.  Use the latter  instead of
the home-grown one.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/sh_eth.c

@@ -2098,8 +2098,8 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 				 skb->len + 2);
 	txdesc->addr = dma_map_single(&ndev->dev, skb->data, skb->len,
 				      DMA_TO_DEVICE);
-	if (skb->len < ETHERSMALL)
-		txdesc->buffer_length = ETHERSMALL;
+	if (skb->len < ETH_ZLEN)
+		txdesc->buffer_length = ETH_ZLEN;
 	else
 		txdesc->buffer_length = skb->len;
 

drivers/net/ethernet/renesas/sh_eth.h

@@ -27,8 +27,7 @@
 #define RX_RING_MIN	64
 #define TX_RING_MAX	1024
 #define RX_RING_MAX	1024
-#define ETHERSMALL		60
-#define PKT_BUF_SZ		1538
+#define PKT_BUF_SZ	1538
 #define SH_ETH_TSU_TIMEOUT_MS	500
 #define SH_ETH_TSU_CAM_ENTRIES	32