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: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/firewire/isight.c

@@ -51,7 +51,6 @@ struct isight {
 	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;