ASoC: Remove unused "control_data" field of struct cs42l51_private

The control_data field is used to initialize the codec's control_data field,
but since this is also done by the snd-soc-cache core, the redundant
assignment can be removed and the field can be dropped.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/cs42l51.c

@@ -42,7 +42,6 @@ enum master_slave_mode {
 
 struct cs42l51_private {
 	enum snd_soc_control_type control_type;
-	void *control_data;
 	unsigned int mclk;
 	unsigned int audio_mode;	/* The mode (I2S or left-justified) */
 	enum master_slave_mode func;
@@ -57,7 +56,7 @@ struct cs42l51_private {
 static int cs42l51_fill_cache(struct snd_soc_codec *codec)
 {
 	u8 *cache = codec->reg_cache + 1;
-	struct i2c_client *i2c_client = codec->control_data;
+	struct i2c_client *i2c_client = to_i2c_client(codec->dev);
 	s32 length;
 
 	length = i2c_smbus_read_i2c_block_data(i2c_client,
@@ -520,8 +519,6 @@ static int cs42l51_probe(struct snd_soc_codec *codec)
 	struct snd_soc_dapm_context *dapm = &codec->dapm;
 	int ret, reg;
 
-	codec->control_data = cs42l51->control_data;
-
 	ret = cs42l51_fill_cache(codec);
 	if (ret < 0) {
 		dev_err(codec->dev, "failed to fill register cache\n");
@@ -593,7 +590,6 @@ static int cs42l51_i2c_probe(struct i2c_client *i2c_client,
 	}
 
 	i2c_set_clientdata(i2c_client, cs42l51);
-	cs42l51->control_data = i2c_client;
 	cs42l51->control_type = SND_SOC_I2C;
 
 	ret =  snd_soc_register_codec(&i2c_client->dev,