ALSA: isight: fix divide error when queueing packets

Set the .header_size field when queueing packets to avoid a division by
zero.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/isight.c

@@ -82,6 +82,7 @@ MODULE_LICENSE("GPL v2");
 static struct fw_iso_packet audio_packet = {
 	.payload_length = sizeof(struct audio_payload),
 	.interrupt = 1,
+	.header_length = 4,
 };
 
 static void isight_update_pointers(struct isight *isight, unsigned int count)