[media] staging: media: omap4iss: video: Don't WARN() on unknown pixel formats

When mapping from a V4L2 pixel format to a media bus format in the
VIDIOC_TRY_FMT and VIDIOC_S_FMT handlers, the requested format may be
unsupported by the driver. Return a hardcoded default format instead of
WARN()ing in that case.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/staging/media/omap4iss/iss_video.c

@@ -171,14 +171,14 @@ static void iss_video_pix_to_mbus(const struct v4l2_pix_format *pix,
 	mbus->width = pix->width;
 	mbus->height = pix->height;
 
-	for (i = 0; i < ARRAY_SIZE(formats); ++i) {
+	/* Skip the last format in the loop so that it will be selected if no
+	 * match is found.
+	 */
+	for (i = 0; i < ARRAY_SIZE(formats) - 1; ++i) {
 		if (formats[i].pixelformat == pix->pixelformat)
 			break;
 	}
 
-	if (WARN_ON(i == ARRAY_SIZE(formats)))
-		return;
-
 	mbus->code = formats[i].code;
 	mbus->colorspace = pix->colorspace;
 	mbus->field = pix->field;