[ALSA] Don't set up the same PID twice in snd_hda_multi_out_analog_prepare

Check the hp_nid whether it's identical with front pin to avoid
the setup of the same widget node twice.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

sound/pci/hda/hda_codec.c

@@ -1942,7 +1942,7 @@ int snd_hda_multi_out_analog_prepare(struct hda_codec *codec, struct hda_multi_o
 
 	/* front */
 	snd_hda_codec_setup_stream(codec, nids[HDA_FRONT], stream_tag, 0, format);
-	if (mout->hp_nid)
+	if (mout->hp_nid && mout->hp_nid != nids[HDA_FRONT])
 		/* headphone out will just decode front left/right (stereo) */
 		snd_hda_codec_setup_stream(codec, mout->hp_nid, stream_tag, 0, format);
 	/* extra outputs copied from front */