class: use IS_ERR_OR_NULL() helper in class_unregister()

Use IS_ERR_OR_NULL() helper in class_unregister() to simplify code.

Signed-off-by: Yang Yingliang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Yang Yingliang

drivers/base/class.c

@@ -260,7 +260,7 @@ EXPORT_SYMBOL_GPL(__class_create);
  */
 void class_destroy(struct class *cls)
 {
-	if ((cls == NULL) || (IS_ERR(cls)))
+	if (IS_ERR_OR_NULL(cls))
 		return;
 
 	class_unregister(cls);