media: rcar_drif: fix a memory disclosure

"f->fmt.sdr.reserved" is uninitialized. As other peer drivers
like msi2500 and airspy do, the fix initializes it to avoid
memory disclosures.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/rcar_drif.c

@@ -912,6 +912,7 @@ static int rcar_drif_g_fmt_sdr_cap(struct file *file, void *priv,
 {
 	struct rcar_drif_sdr *sdr = video_drvdata(file);
 
+	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
 	f->fmt.sdr.pixelformat = sdr->fmt->pixelformat;
 	f->fmt.sdr.buffersize = sdr->fmt->buffersize;