ASoC: codecs: rt5660: Simplify mclk initialization

Most of clk_xxx() functions do check if provided clk-pointer is
non-NULL. These do not check if the pointer is an error-pointer.
Providing such to a clk_xxx() results in a panic.

By utilizing _optional() variant of devm_clk_get() the driver code is
both simplified and more robust. There is no need to remember about
IS_ERR(clk) checks each time mclk is accessed.
Reviewed-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://msgid.link/r/20240221152516.852353-7-cezary.rojewski@intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rt5660.c

@@ -1079,9 +1079,6 @@ static int rt5660_set_bias_level(struct snd_soc_component *component,
 		snd_soc_component_update_bits(component, RT5660_GEN_CTRL1,
 			RT5660_DIG_GATE_CTRL, RT5660_DIG_GATE_CTRL);
 
-		if (IS_ERR(rt5660->mclk))
-			break;
-
 		if (snd_soc_component_get_bias_level(component) == SND_SOC_BIAS_ON) {
 			clk_disable_unprepare(rt5660->mclk);
 		} else {
@@ -1277,9 +1274,9 @@ static int rt5660_i2c_probe(struct i2c_client *i2c)
 		return -ENOMEM;
 
 	/* Check if MCLK provided */
-	rt5660->mclk = devm_clk_get(&i2c->dev, "mclk");
-	if (PTR_ERR(rt5660->mclk) == -EPROBE_DEFER)
-		return -EPROBE_DEFER;
+	rt5660->mclk = devm_clk_get_optional(&i2c->dev, "mclk");
+	if (IS_ERR(rt5660->mclk))
+		return PTR_ERR(rt5660->mclk);
 
 	i2c_set_clientdata(i2c, rt5660);