ALSA: emu10k1: remove unused snd_emu10k1_voice.emu field

It was written, but never read from. Its value is available via the epcm
field.
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230421141006.1005452-5-oswald.buddenhagen@gmx.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/emu10k1.h

@@ -1485,7 +1485,6 @@ enum {
 struct snd_emu10k1;
 
 struct snd_emu10k1_voice {
-	struct snd_emu10k1 *emu;
 	int number;
 	unsigned int use: 1,
 	    pcm: 1,

sound/pci/emu10k1/emu10k1_main.c

@@ -1971,10 +1971,8 @@ int snd_emu10k1_create(struct snd_card *card,
 		pgtbl[idx] = cpu_to_le32(silent_page | idx);
 
 	/* set up voice indices */
-	for (idx = 0; idx < NUM_G; idx++) {
-		emu->voices[idx].emu = emu;
+	for (idx = 0; idx < NUM_G; idx++)
 		emu->voices[idx].number = idx;
-	}
 
 	err = snd_emu10k1_init(emu, enable_ir, 0);
 	if (err < 0)

sound/pci/emu10k1/p16v.c

@@ -181,7 +181,6 @@ static int snd_p16v_pcm_open_playback_channel(struct snd_pcm_substream *substrea
   
 	runtime->hw = snd_p16v_playback_hw;
 
-        channel->emu = emu;
         channel->number = channel_id;
 
         channel->use=1;
@@ -230,7 +229,6 @@ static int snd_p16v_pcm_open_capture_channel(struct snd_pcm_substream *substream
   
 	runtime->hw = snd_p16v_capture_hw;
 
-	channel->emu = emu;
 	channel->number = channel_id;
 
 	channel->use=1;