netdev: convert non-obvious instances to use ARRAY_SIZE()

This will convert remaining non-obvious or naive calculations of array
sizes to use ARRAY_SIZE() macro.

Signed-off-by: Alejandro Martinez Ruiz <alex@flawedcode.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 30b1cca..76efb3f 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -9034,7 +9034,7 @@
 	int i;
 	u32 j;
 
-	for (i = 0; i < sizeof(test_pattern)/sizeof(u32); i++) {
+	for (i = 0; i < ARRAY_SIZE(test_pattern); i++) {
 		for (j = 0; j < len; j += 4) {
 			u32 val;