ASoC: soc-core: tidyup for snd_soc_add_component_controls()

snd_soc_add_component_controls() registers controls by using
for(... i < num; ...). If controls was NULL, num should be zero.
Thus, we don't need to check about controls pointer.
This patch also cares missing return value.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87ef1xahor.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-core.c

@@ -1304,10 +1304,12 @@ static int soc_probe_component(struct snd_soc_card *card,
 		}
 	}
 
-	if (component->driver->controls)
-		snd_soc_add_component_controls(component,
-					       component->driver->controls,
-					       component->driver->num_controls);
+	ret = snd_soc_add_component_controls(component,
+					     component->driver->controls,
+					     component->driver->num_controls);
+	if (ret < 0)
+		goto err_probe;
+
 	if (component->driver->dapm_routes)
 		snd_soc_dapm_add_routes(dapm,
 					component->driver->dapm_routes,