ALSA: 6fire: Release resources at card release

ALSA: 6fire: Release resources at card release

The current 6fire code tries to release the resources right after the
call of usb6fire_chip_abort().  But at this moment, the card object
might be still in use (as we're calling snd_card_free_when_closed()).

For avoid potential UAFs, move the release of resources to the card's
private_free instead of the manual call of usb6fire_chip_destroy() at
the USB disconnect callback.

Fixes: c6d43ba816d1 ("ALSA: usb/6fire - Driver for TerraTec DMX 6Fire USB")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20241113111042.15058-6-tiwai@suse.de