kobject: explain what kobject's sd field is

ulfalizer · gregkh · commit f7025709e29a · 2015-10-04T11:46:16.000+01:00
(More) unclear, especially name-wise, after sysfs_dirent became
kernfs_node.

Signed-off-by: Ulf Magnusson &lt;ulfalizer@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
@@ -66,7 +66,7 @@ struct kobject {
 	struct kobject		*parent;
 	struct kset		*kset;
 	struct kobj_type	*ktype;
-	struct kernfs_node	*sd;
+	struct kernfs_node	*sd; /* sysfs directory entry */
 	struct kref		kref;
 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
 	struct delayed_work	release;
