V4L/DVB (4585): VIDIOC_G_SLICED_VBI_CAP now accepts a v4l2_buf_type, make it IOWR

The VIDIOC_G_SLICED_VBI_CAP needs to receive the v4l2_buf_type field before
it can return a result. Hence this ioctl must be IOWR, not IOR. Since this
ioctl is still marked experimental we can make this change.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

include/linux/videodev2.h

@@ -1243,7 +1243,7 @@ struct v4l2_streamparm
 #define VIDIOC_G_PRIORITY       _IOR  ('V', 67, enum v4l2_priority)
 #define VIDIOC_S_PRIORITY       _IOW  ('V', 68, enum v4l2_priority)
 #if 1
-#define VIDIOC_G_SLICED_VBI_CAP _IOR  ('V', 69, struct v4l2_sliced_vbi_cap)
+#define VIDIOC_G_SLICED_VBI_CAP _IOWR ('V', 69, struct v4l2_sliced_vbi_cap)
 #endif
 #define VIDIOC_LOG_STATUS       _IO   ('V', 70)
 #define VIDIOC_G_EXT_CTRLS	_IOWR ('V', 71, struct v4l2_ext_controls)