ar71xx: use ETH_ALEN for consistency

Signed-off-by: Forest Crossman <cyrozap@gmail.com>

Backport of r42280

git-svn-id: svn://svn.openwrt.org/openwrt/branches/barrier_breaker@42381 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/ar71xx/files/arch/mips/ath79/mach-esr900.c

@@ -145,9 +145,9 @@ static void __init esr900_setup(void)
 {
 	const char *config = (char *) KSEG1ADDR(ESR900_CONFIG_ADDR);
 	u8 *art = (u8 *) KSEG1ADDR(ESR900_CALDATA_ADDR);
-	u8 lan_mac[6];
-	u8 wlan0_mac[6];
-	u8 wlan1_mac[6];
+	u8 lan_mac[ETH_ALEN];
+	u8 wlan0_mac[ETH_ALEN];
+	u8 wlan1_mac[ETH_ALEN];
 
 	if (ath79_nvram_parse_mac_addr(config, ESR900_CONFIG_SIZE,
 				       "ethaddr=", lan_mac) == 0) {