ASoC: dapm: Check return value of snd_soc_cnew()

snd_soc_cnew() can return NULL, so we should check the result before trying to
use it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/soc-dapm.c

@@ -671,8 +671,10 @@ static int dapm_create_or_share_mixmux_kcontrol(struct snd_soc_dapm_widget *w,
 
 		kcontrol = snd_soc_cnew(&w->kcontrol_news[kci], NULL, name,
 					prefix);
-		kcontrol->private_free = dapm_kcontrol_free;
 		kfree(long_name);
+		if (!kcontrol)
+			return -ENOMEM;
+		kcontrol->private_free = dapm_kcontrol_free;
 
 		ret = dapm_kcontrol_data_alloc(w, kcontrol);
 		if (ret) {