[Patch] hdac_sysfs: Fix a memory leaking bug in sound/hda/hdac_sysfs.c file of Linux 5.1

[Gen Zhang <blackgod016574@gmail.com>]

tree->root and tree->nodes are allocated by memory allocation 
functions. And tree is also an allocated memory. When allocation of 
tree->root and tree->nodes fails, not freeing tree will leak memory. 
Thus we should free tree in this situation.

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>

---
diff --git a/sound/hda/hdac_sysfs.c b/sound/hda/hdac_sysfs.c
index fb2aa34..5d8a939 100644
--- a/sound/hda/hdac_sysfs.c
+++ b/sound/hda/hdac_sysfs.c
@@ -370,12 +370,12 @@ static int widget_tree_create(struct hdac_device *codec)
 
 	tree->root = kobject_create_and_add("widgets", &codec->dev.kobj);
 	if (!tree->root)
-		return -ENOMEM;
+		goto free_tree;
 
 	tree->nodes = kcalloc(codec->num_nodes + 1, sizeof(*tree->nodes),
 			      GFP_KERNEL);
 	if (!tree->nodes)
-		return -ENOMEM;
+		goto free_tree;
 
 	for (i = 0, nid = codec->start_nid; i < codec->num_nodes; i++, nid++) {
 		err = add_widget_node(tree->root, nid, &widget_node_group,
@@ -393,6 +393,9 @@ static int widget_tree_create(struct hdac_device *codec)
 
 	kobject_uevent(tree->root, KOBJ_CHANGE);
 	return 0;
+free_tree:
+	kfree(tree);
+	return -ENOMEM;
 }
 
 int hda_widget_sysfs_init(struct hdac_device *codec)
---