net: cosmetic: Do not use magic values for ARP_HLEN

Commit 674bb249825a ("net: cosmetic: Replace magic numbers in arp.c with
constants") introduced a nice define to replace the magic value 6 for
the ethernet hardware address. Replace more hardcoded instances of 6
which really reference the ARP_HLEN (iow the MAC/Hardware/Ethernet
address).

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/net/eth-uclass.c b/net/eth-uclass.c
index 1d13011..140e47d 100644
--- a/net/eth-uclass.c
+++ b/net/eth-uclass.c
@@ -230,7 +230,7 @@
 			eth_write_hwaddr(dev);
 			break;
 		case env_op_delete:
-			memset(pdata->enetaddr, 0, 6);
+			memset(pdata->enetaddr, 0, ARP_HLEN);
 		}
 	}
 
@@ -458,7 +458,7 @@
 {
 	struct eth_device_priv *priv = dev->uclass_priv;
 	struct eth_pdata *pdata = dev->platdata;
-	unsigned char env_enetaddr[6];
+	unsigned char env_enetaddr[ARP_HLEN];
 
 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 	struct eth_ops *ops = eth_get_ops(dev);
@@ -497,7 +497,7 @@
 	eth_getenv_enetaddr_by_index("eth", dev->seq, env_enetaddr);
 	if (!is_zero_ethaddr(env_enetaddr)) {
 		if (!is_zero_ethaddr(pdata->enetaddr) &&
-		    memcmp(pdata->enetaddr, env_enetaddr, 6)) {
+		    memcmp(pdata->enetaddr, env_enetaddr, ARP_HLEN)) {
 			printf("\nWarning: %s MAC addresses don't match:\n",
 			       dev->name);
 			printf("Address in SROM is         %pM\n",
@@ -507,7 +507,7 @@
 		}
 
 		/* Override the ROM MAC address */
-		memcpy(pdata->enetaddr, env_enetaddr, 6);
+		memcpy(pdata->enetaddr, env_enetaddr, ARP_HLEN);
 	} else if (is_valid_ethaddr(pdata->enetaddr)) {
 		eth_setenv_enetaddr_by_index("eth", dev->seq, pdata->enetaddr);
 		printf("\nWarning: %s using MAC address from ROM\n",
@@ -535,7 +535,7 @@
 	eth_get_ops(dev)->stop(dev);
 
 	/* clear the MAC address */
-	memset(pdata->enetaddr, 0, 6);
+	memset(pdata->enetaddr, 0, ARP_HLEN);
 
 	return 0;
 }