ALSA: hda: fix some klockwork scan warnings

This patch fixes some warnings from klockwork.

These warnings are not the real issues. The patch
adds the sanity check.

Signed-off-by: Libin Yang <libin.yang@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_codec.c

@@ -3584,6 +3584,12 @@ static void setup_dig_out_stream(struct hda_codec *codec, hda_nid_t nid,
 	bool reset;
 
 	spdif = snd_hda_spdif_out_of_nid(codec, nid);
+	/* Add sanity check to pass klockwork check.
+	 * This should never happen.
+	 */
+	if (WARN_ON(spdif == NULL))
+		return;
+
 	curr_fmt = snd_hda_codec_read(codec, nid, 0,
 				      AC_VERB_GET_STREAM_FORMAT, 0);
 	reset = codec->spdif_status_reset &&
@@ -3768,7 +3774,7 @@ int snd_hda_multi_out_analog_prepare(struct hda_codec *codec,
 	spdif = snd_hda_spdif_out_of_nid(codec, mout->dig_out_nid);
 	if (mout->dig_out_nid && mout->share_spdif &&
 	    mout->dig_out_used != HDA_DIG_EXCLUSIVE) {
-		if (chs == 2 &&
+		if (chs == 2 && spdif != NULL &&
 		    snd_hda_is_supported_format(codec, mout->dig_out_nid,
 						format) &&
 		    !(spdif->status & IEC958_AES0_NONAUDIO)) {

sound/pci/hda/patch_hdmi.c

@@ -1680,6 +1680,11 @@ static bool check_non_pcm_per_cvt(struct hda_codec *codec, hda_nid_t cvt_nid)
 
 	mutex_lock(&codec->spdif_mutex);
 	spdif = snd_hda_spdif_out_of_nid(codec, cvt_nid);
+	/* Add sanity check to pass klockwork check.
+	 * This should never happen.
+	 */
+	if (WARN_ON(spdif == NULL))
+		return true;
 	non_pcm = !!(spdif->status & IEC958_AES0_NONAUDIO);
 	mutex_unlock(&codec->spdif_mutex);
 	return non_pcm;