ASoC: rt286: Fix run time error while modifying const data

Make a copy of memory for index_cache rather than directly use the
rt286_index_def to avoid run time error.

Fixes: c418a84a8c8f ("ASoC: Constify reg_default tables")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rt286.c

@@ -38,7 +38,7 @@
 #define RT288_VENDOR_ID 0x10ec0288
 
 struct rt286_priv {
-	const struct reg_default *index_cache;
+	struct reg_default *index_cache;
 	int index_cache_size;
 	struct regmap *regmap;
 	struct snd_soc_codec *codec;
@@ -1161,7 +1161,11 @@ static int rt286_i2c_probe(struct i2c_client *i2c,
 		return -ENODEV;
 	}
 
-	rt286->index_cache = rt286_index_def;
+	rt286->index_cache = devm_kmemdup(&i2c->dev, rt286_index_def,
+					  sizeof(rt286_index_def), GFP_KERNEL);
+	if (!rt286->index_cache)
+		return -ENOMEM;
+
 	rt286->index_cache_size = INDEX_CACHE_SIZE;
 	rt286->i2c = i2c;
 	i2c_set_clientdata(i2c, rt286);