net: cosmetic: Name ethaddr variables consistently

Use "_ethaddr" at the end of variables and drop CamelCase.
Make constant values actually 'const'.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/net/macb.c b/drivers/net/macb.c
index 170ff06..1fe408c 100644
--- a/drivers/net/macb.c
+++ b/drivers/net/macb.c
@@ -595,7 +595,7 @@
 	}
 
 	/* update the ethaddr */
-	if (is_valid_ether_addr(netdev->enetaddr)) {
+	if (is_valid_ethaddr(netdev->enetaddr)) {
 		macb_write_hwaddr(netdev);
 	} else {
 		printf("%s: mac address is not valid\n", netdev->name);