netdev: ARRAY_SIZE() cleanups

Convert array size calculations to use ARRAY_SIZE().

Signed-off-by: Alejandro Martinez Ruiz <alex@flawedcode.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/wireless/ipw2100.c b/drivers/net/wireless/ipw2100.c
index fc6cdd8..dc3813b 100644
--- a/drivers/net/wireless/ipw2100.c
+++ b/drivers/net/wireless/ipw2100.c
@@ -6591,8 +6591,7 @@
 	2472, 2484
 };
 
-#define FREQ_COUNT (sizeof(ipw2100_frequencies) / \
-                    sizeof(ipw2100_frequencies[0]))
+#define FREQ_COUNT	ARRAY_SIZE(ipw2100_frequencies)
 
 static const long ipw2100_rates_11b[] = {
 	1000000,