sysfs-tagging.txt: fix pre-kernfs references

 - sysfs_dirent is now kernfs_node - see commit 324a56e1 ("kernfs:
   s/sysfs_dirent/kernfs_node/ and rename its friends accordingly")

 - sysfs_super_info is now kernfs_super_info - see commit c525aadd
   ("kernfs: s/sysfs/kernfs/ in various data structures")

 - the 's_' prefix was dropped from various fields - see
   commit adc5e8b5 ("kernfs: drop s_ prefix from kernfs_node members")
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/filesystems/sysfs-tagging.txt

@@ -17,13 +17,13 @@ the sysfs directory entries we ensure that we don't have conflicts
 in the directories and applications only see a limited set of
 the network devices.
 
-Each sysfs directory entry may be tagged with zero or one
-namespaces.  A sysfs_dirent is augmented with a void *s_ns.  If a
-directory entry is tagged, then sysfs_dirent->s_flags will have a
-flag between KOBJ_NS_TYPE_NONE and KOBJ_NS_TYPES, and s_ns will
-point to the namespace to which it belongs.
+Each sysfs directory entry may be tagged with a namespace via the
+void *ns member of its kernfs_node.  If a directory entry is tagged,
+then kernfs_node->flags will have a flag between KOBJ_NS_TYPE_NONE
+and KOBJ_NS_TYPES, and ns will point to the namespace to which it
+belongs.
 
-Each sysfs superblock's sysfs_super_info contains an array void
+Each sysfs superblock's kernfs_super_info contains an array void
 *ns[KOBJ_NS_TYPES].  When a task in a tagging namespace
 kobj_nstype first mounts sysfs, a new superblock is created.  It
 will be differentiated from other sysfs mounts by having its
@@ -31,7 +31,7 @@ s_fs_info->ns[kobj_nstype] set to the new namespace.  Note that
 through bind mounting and mounts propagation, a task can easily view
 the contents of other namespaces' sysfs mounts.  Therefore, when a
 namespace exits, it will call kobj_ns_exit() to invalidate any
-sysfs_dirent->s_ns pointers pointing to it.
+kernfs_node->ns pointers pointing to it.
 
 Users of this interface:
 - define a type in the kobj_ns_type enumeration.