media: usb: hdpvr: Store v4l2_fh pointer in file->private_data

media: usb: hdpvr: Store v4l2_fh pointer in file->private_data

Most V4L2 drivers store the v4l2_fh pointer in file->private_data. The
hdpvr driver instead stores the pointer to the driver-specific structure
that embeds the v4l2_fh. Switch to storing the v4l2_fh pointer itself to
standardize behaviour across drivers. This also prepares for future
refactoring that depends on v4l2_fh being stored in private_data.

No extensive driver refactoring is required, as file->private_data is
only used to check if a file handle is the owner of the device by
comparing pointer values. The private_data pointer is actually compared
to a struct v4l2_fh pointer, which happens to be the first field of the
hdpvr_fh structure.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>