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>

sound/pci/rme9652/hdsp.c

@@ -4845,6 +4845,7 @@ static int snd_hdsp_hwdep_ioctl(struct snd_hwdep *hw, struct file *file, unsigne
 			if ((err = hdsp_get_iobox_version(hdsp)) < 0)
 				return err;
 		}
+		memset(&hdsp_version, 0, sizeof(hdsp_version));
 		hdsp_version.io_type = hdsp->io_type;
 		hdsp_version.firmware_rev = hdsp->firmware_rev;
 		if ((err = copy_to_user(argp, &hdsp_version, sizeof(hdsp_version))))