atm: Use ARRAY_SIZE macro when appropriate

Use ARRAY_SIZE macro already defined in kernel.h for ATM
drivers.

Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: chas williams <chas@cmf.nrl.navy.mil>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/atm/he.c b/drivers/atm/he.c
index db33f6f..8510026 100644
--- a/drivers/atm/he.c
+++ b/drivers/atm/he.c
@@ -3017,7 +3017,7 @@
 	he_writel(he_dev, val, HOST_CNTL);
        
 	/* Send READ instruction */
-	for (i = 0; i < sizeof(readtab)/sizeof(readtab[0]); i++) {
+	for (i = 0; i < ARRAY_SIZE(readtab); i++) {
 		he_writel(he_dev, val | readtab[i], HOST_CNTL);
 		udelay(EEPROM_DELAY);
 	}