ALSA: hdsp - info leak in snd_hdsp_hwdep_ioctl()

In GCC the sizeof(hdsp_version) is 8 because there is a 2 byte hole at
the end of the struct after ->firmware_rev.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>