media: pci: ivtv: Don't create fake v4l2_fh

media: pci: ivtv: Don't create fake v4l2_fh

The ivtv driver has a structure named ivtv_open_id that models an open
file handle for the device. It embeds a v4l2_fh instance for file
handles that correspond to a V4L2 video device, and stores a pointer to
that v4l2_fh in struct ivtv_stream to identify which open file handle
owns a particular stream.

In addition to video devices, streams can be owned by ALSA PCM devices.
Those devices do not make use of the v4l2_fh instance for obvious
reasons, but the snd_ivtv_pcm_capture_open() function still initializes
a "fake" v4l2_fh for the sole purpose of using it as an open file handle
identifier. The v4l2_fh is not properly destroyed when the ALSA PCM
device is closed, leading to possible resource leaks.

Fortunately, the v4l2_fh instance pointed to by ivtv_stream is not
accessed, only the pointer value is used for comparison. Replace it with
a pointer to the ivtv_open_id structure that embeds the v4l2_fh, and
don't initialize the v4l2_fh for ALSA PCM devices.

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