lib/test-kstrtox.c: use ARRAY_SIZE instead of sizeof/sizeof[0]

Use kernel.h definition.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test-kstrtox.c

@@ -3,7 +3,7 @@
 #include <linux/module.h>
 
 #define for_each_test(i, test)	\
-	for (i = 0; i < sizeof(test) / sizeof(test[0]); i++)
+	for (i = 0; i < ARRAY_SIZE(test); i++)
 
 struct test_fail {
 	const char *str;