ALSA: hda: Delete an unnecessary check before the function call "kobject_put"

The kobject_put() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/hda/hdac_sysfs.c

@@ -321,8 +321,7 @@ static void widget_tree_free(struct hdac_device *codec)
 			free_widget_node(*p, &widget_node_group);
 		kfree(tree->nodes);
 	}
-	if (tree->root)
-		kobject_put(tree->root);
+	kobject_put(tree->root);
 	kfree(tree);
 	codec->widgets = NULL;
 }