ALSA: isight: remove superfluous field

Remove a field that is not used at all.  This remained from
earlier tests, but the current driver has decided not to handle
iris notifications.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/firewire/isight.c b/sound/firewire/isight.c
index 4400308..cd094ec 100644
--- a/sound/firewire/isight.c
+++ b/sound/firewire/isight.c
@@ -51,7 +51,6 @@
 	struct fw_unit *unit;
 	struct fw_device *device;
 	u64 audio_base;
-	struct fw_address_handler iris_handler;
 	struct snd_pcm_substream *pcm;
 	struct mutex mutex;
 	struct iso_packets_buffer buffer;