ethernet: Convert mac address uses of 6 to ETH_ALEN

Use the normal #define to help grep find mac addresses
and ensure that addresses are aligned.

pasemi.h has an unaligned access to mac_addr, unchanged
for now.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Olof Johansson <olof@lixom.net> # pasemi_mac pieces
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/amd/pcnet32.c b/drivers/net/ethernet/amd/pcnet32.c
index ed21307..2d8e288 100644
--- a/drivers/net/ethernet/amd/pcnet32.c
+++ b/drivers/net/ethernet/amd/pcnet32.c
@@ -1521,7 +1521,7 @@
 	char *chipname;
 	struct net_device *dev;
 	const struct pcnet32_access *a = NULL;
-	u8 promaddr[6];
+	u8 promaddr[ETH_ALEN];
 	int ret = -ENODEV;
 
 	/* reset the chip */
@@ -1665,10 +1665,10 @@
 	}
 
 	/* read PROM address and compare with CSR address */
-	for (i = 0; i < 6; i++)
+	for (i = 0; i < ETH_ALEN; i++)
 		promaddr[i] = inb(ioaddr + i);
 
-	if (memcmp(promaddr, dev->dev_addr, 6) ||
+	if (memcmp(promaddr, dev->dev_addr, ETH_ALEN) ||
 	    !is_valid_ether_addr(dev->dev_addr)) {
 		if (is_valid_ether_addr(promaddr)) {
 			if (pcnet32_debug & NETIF_MSG_PROBE) {