ASoC: zx296702-i2s: Fix resource leak when unload module

Use devm_* API to fix leaks in current code.
1. Use devm_kzalloc to fix memory leak for zx_i2s when unload the module.
2. Use devm_snd_soc_register_component to ensure component is unregistered
   when unload the module.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/zte/zx296702-i2s.c

@@ -380,7 +380,7 @@ static int zx_i2s_probe(struct platform_device *pdev)
 	struct zx_i2s_info *zx_i2s;
 	int ret;
 
-	zx_i2s =  kzalloc(sizeof(*zx_i2s), GFP_KERNEL);
+	zx_i2s = devm_kzalloc(&pdev->dev, sizeof(*zx_i2s), GFP_KERNEL);
 	if (!zx_i2s)
 		return -ENOMEM;
 
@@ -401,8 +401,8 @@ static int zx_i2s_probe(struct platform_device *pdev)
 	writel_relaxed(0, zx_i2s->reg_base + ZX_I2S_FIFO_CTRL);
 	platform_set_drvdata(pdev, zx_i2s);
 
-	ret = snd_soc_register_component(&pdev->dev, &zx_i2s_component,
-					 &zx_i2s_dai, 1);
+	ret = devm_snd_soc_register_component(&pdev->dev, &zx_i2s_component,
+					      &zx_i2s_dai, 1);
 	if (ret) {
 		dev_err(&pdev->dev, "Register DAI failed: %d\n", ret);
 		return ret;