[media] s2255drv: fix payload size for JPG, MJPEG

length is the size of the buffer, not the payload. That's set using
vb2_set_plane_payload().
Signed-off-by: NDean Anderson <linux-dev@sensoray.com>
Cc: <stable@vger.kernel.org>      # for v3.15 and up
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/usb/s2255/s2255drv.c

@@ -632,7 +632,7 @@ static void s2255_fillbuff(struct s2255_vc *vc,
 			break;
 		case V4L2_PIX_FMT_JPEG:
 		case V4L2_PIX_FMT_MJPEG:
-			buf->vb.v4l2_buf.length = jpgsize;
+			vb2_set_plane_payload(&buf->vb, 0, jpgsize);
 			memcpy(vbuf, tmpbuf, jpgsize);
 			break;
 		case V4L2_PIX_FMT_YUV422P: