ASoC: topology: Check widget kcontrols before deref

Validate the topology input before we dereference the pointer.
Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-topology.c

@@ -513,7 +513,7 @@ static void remove_widget(struct snd_soc_component *comp,
 	 */
 	if (dobj->widget.kcontrol_type == SND_SOC_TPLG_TYPE_ENUM) {
 		/* enumerated widget mixer */
-		for (i = 0; i < w->num_kcontrols; i++) {
+		for (i = 0; w->kcontrols != NULL && i < w->num_kcontrols; i++) {
 			struct snd_kcontrol *kcontrol = w->kcontrols[i];
 			struct soc_enum *se =
 				(struct soc_enum *)kcontrol->private_value;
@@ -530,7 +530,7 @@ static void remove_widget(struct snd_soc_component *comp,
 		}
 	} else {
 		/* volume mixer or bytes controls */
-		for (i = 0; i < w->num_kcontrols; i++) {
+		for (i = 0; w->kcontrols != NULL && i < w->num_kcontrols; i++) {
 			struct snd_kcontrol *kcontrol = w->kcontrols[i];
 
 			if (dobj->widget.kcontrol_type