ASoC: wm9712: Use empty struct initializer

{ 0 } only clears the first member of the structure.

The first member of the snd_soc_dapm_update struct is a pointer,
and writing 0 to a pointer results in the following sparse warning:

sound/soc/codecs/wm9712.c:229:47: warning: Using plain integer as NULL pointer

Use the empty struct initializer that clears all the struct members
and fixes the sparse warning.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm9712.c

@@ -226,7 +226,7 @@ static int wm9712_hp_mixer_put(struct snd_kcontrol *kcontrol,
 	struct soc_mixer_control *mc =
 		(struct soc_mixer_control *)kcontrol->private_value;
 	unsigned int mixer, mask, shift, old;
-	struct snd_soc_dapm_update update = { 0 };
+	struct snd_soc_dapm_update update = {};
 	bool change;
 
 	mixer = mc->shift >> 8;