ASoC: test-component: fix null pointer dereference.

Dereferncing of_id pointer will result in exception in current
implementation since of_match_device() will assign it to NULL.
Adding NULL check for protection.

Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
Link: https://lore.kernel.org/r/20211205204200.7852-1-amhamza.mgc@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: amer-hamza

sound/soc/generic/test-component.c

@@ -532,13 +532,16 @@ static int test_driver_probe(struct platform_device *pdev)
 	struct device_node *node = dev->of_node;
 	struct device_node *ep;
 	const struct of_device_id *of_id = of_match_device(test_of_match, &pdev->dev);
-	const struct test_adata *adata = of_id->data;
+	const struct test_adata *adata;
 	struct snd_soc_component_driver *cdriv;
 	struct snd_soc_dai_driver *ddriv;
 	struct test_dai_name *dname;
 	struct test_priv *priv;
 	int num, ret, i;
 
+	if (!of_id)
+		return -EINVAL;
+	adata = of_id->data;
 	num = of_graph_get_endpoint_count(node);
 	if (!num) {
 		dev_err(dev, "no port exits\n");