ALSA: hda - Fix conflict of d-mic capture volume controls

When the d-mics are assigned to the same purpose of another analog mic
pins, the driver doesn't compute the index properly, resulting in an
error with "existing control".  This patch fixes it.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/pci/hda/patch_sigmatel.c

@@ -3481,6 +3481,8 @@ static int stac92xx_auto_create_dmic_input_ctls(struct hda_codec *codec,
 
 		label = hda_get_input_pin_label(codec, nid, 1);
 		snd_hda_add_imux_item(dimux, label, index, &type_idx);
+		if (snd_hda_get_bool_hint(codec, "separate_dmux") != 1)
+			snd_hda_add_imux_item(imux, label, index, &type_idx);
 
 		err = create_elem_capture_vol(codec, nid, label, type_idx,
 					      HDA_INPUT);
@@ -3492,9 +3494,6 @@ static int stac92xx_auto_create_dmic_input_ctls(struct hda_codec *codec,
 			if (err < 0)
 				return err;
 		}
-
-		if (snd_hda_get_bool_hint(codec, "separate_dmux") != 1)
-			snd_hda_add_imux_item(imux, label, index, NULL);
 	}
 
 	return 0;