ASoC: soc-core: snd_soc_rtdcom_lookup() cares component driver name

snd_soc_rtdcom_lookup() look up component by uisng driver name.
Then, it uses component->driver->name.
Some driver might doesn't have it, thus it should care NULL pointer.
This patch solve this issue.

Reported-by: Mukunda,Vijendar <vijendar.mukunda@amd.com>
Reported-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Mukunda,Vijendar <vijendar.mukunda@amd.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-core.c

@@ -590,9 +590,17 @@ struct snd_soc_component *snd_soc_rtdcom_lookup(struct snd_soc_pcm_runtime *rtd,
 {
 	struct snd_soc_rtdcom_list *rtdcom;
 
+	if (!driver_name)
+		return NULL;
+
 	for_each_rtdcom(rtd, rtdcom) {
-		if ((rtdcom->component->driver->name == driver_name) ||
-		    strcmp(rtdcom->component->driver->name, driver_name) == 0)
+		const char *component_name = rtdcom->component->driver->name;
+
+		if (!component_name)
+			continue;
+
+		if ((component_name == driver_name) ||
+		    strcmp(component_name, driver_name) == 0)
 			return rtdcom->component;
 	}