ethernet: Convert ETHER_ADDR_LEN uses to ETH_ALEN

Reduce the number of #defines, use the normal #define from if_ether.h

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/8390/hydra.c b/drivers/net/ethernet/8390/hydra.c
index 3dac937..5370c88 100644
--- a/drivers/net/ethernet/8390/hydra.c
+++ b/drivers/net/ethernet/8390/hydra.c
@@ -129,7 +129,7 @@
     if (!dev)
 	return -ENOMEM;
 
-    for(j = 0; j < ETHER_ADDR_LEN; j++)
+    for (j = 0; j < ETH_ALEN; j++)
 	dev->dev_addr[j] = *((u8 *)(board + HYDRA_ADDRPROM + 2*j));
 
     /* We must set the 8390 for word mode. */