media: use ARRAY_SIZE

Using the ARRAY_SIZE macro improves the readability of the code. Also,
it is not always useful to use a variable to store this constant
calculated at compile time.

Found with Coccinelle with the following semantic patch:
@r depends on (org || report)@
type T;
T[] E;
position p;
@@
(
 (sizeof(E)@p /sizeof(*E))
|
 (sizeof(E)@p /sizeof(E[...]))
|
 (sizeof(E)@p /sizeof(T))
)

Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Reviewed-by: Michael Ira Krufky <mkrufky@linuxtv.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/common/saa7146/saa7146_video.c

@@ -4,6 +4,7 @@
 #include <media/v4l2-event.h>
 #include <media/v4l2-ctrls.h>
 #include <linux/module.h>
+#include <linux/kernel.h>
 
 static int max_memory = 32;
 
@@ -86,13 +87,11 @@ static struct saa7146_format formats[] = {
    due to this, it's impossible to provide additional *packed* formats, which are simply byte swapped
    (like V4L2_PIX_FMT_YUYV) ... 8-( */
 
-static int NUM_FORMATS = sizeof(formats)/sizeof(struct saa7146_format);
-
 struct saa7146_format* saa7146_format_by_fourcc(struct saa7146_dev *dev, int fourcc)
 {
-	int i, j = NUM_FORMATS;
+	int i;
 
-	for (i = 0; i < j; i++) {
+	for (i = 0; i < ARRAY_SIZE(formats); i++) {
 		if (formats[i].pixelformat == fourcc) {
 			return formats+i;
 		}
@@ -524,7 +523,7 @@ static int vidioc_s_fbuf(struct file *file, void *fh, const struct v4l2_framebuf
 
 static int vidioc_enum_fmt_vid_cap(struct file *file, void *fh, struct v4l2_fmtdesc *f)
 {
-	if (f->index >= NUM_FORMATS)
+	if (f->index >= ARRAY_SIZE(formats))
 		return -EINVAL;
 	strlcpy((char *)f->description, formats[f->index].name,
 			sizeof(f->description));