[media] v4l2-subdev.h: fix a typo at a kernel-doc markup

One struct at the comment was not written well.

Fix it.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

include/media/v4l2-subdev.h

@@ -421,7 +421,7 @@ struct v4l2_subdev_video_ops {
  *				  in video mode via the vbi device node.
  *
  *  @decode_vbi_line: video decoders that support sliced VBI need to implement
- *	this ioctl. Field p of the &struct v4l2_sliced_vbi_line is set to the
+ *	this ioctl. Field p of the &struct v4l2_decode_vbi_line is set to the
  *	start of the VBI data that was generated by the decoder. The driver
  *	then parses the sliced VBI data and sets the other fields in the
  *	struct accordingly. The pointer p is updated to point to the start of