ASoC: wm2000: Get the CODEC pointer from the widget

Don't rely on the kcontrol for robustness reasons, the widget mechanism
is what the framework uses.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/wm2000.c b/sound/soc/codecs/wm2000.c
index 683dc43..02750ab 100644
--- a/sound/soc/codecs/wm2000.c
+++ b/sound/soc/codecs/wm2000.c
@@ -646,7 +646,7 @@
 static int wm2000_anc_power_event(struct snd_soc_dapm_widget *w,
 				  struct snd_kcontrol *kcontrol, int event)
 {
-	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
+	struct snd_soc_codec *codec = w->codec;
 	struct wm2000_priv *wm2000 = dev_get_drvdata(codec->dev);
 
 	if (SND_SOC_DAPM_EVENT_ON(event))