ALSA: usb/quirks, fix out-of-bounds access

bootresponse in snd_usb_mbox2_boot_quirk is only 12 (decimal) u8's
long, but i9s passed to snd_usb_ctl_msg as it would be 0x12 (hexa)
long. Fix that by having proper size of the array, i.e. 0x12.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/quirks.c

@@ -533,7 +533,7 @@ static int snd_usb_mbox2_boot_quirk(struct usb_device *dev)
 {
 	struct usb_host_config *config = dev->actconfig;
 	int err;
-	u8 bootresponse[12];
+	u8 bootresponse[0x12];
 	int fwsize;
 	int count;