proc: use rb_entry()

To make the code clearer, use rb_entry() instead of container_of() to
deal with rbtree.

Link: http://lkml.kernel.org/r/4fd1f82818665705ce75c5156a060ae7caa8e0a9.1482160150.git.geliangtang@gmail.com
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/generic.c

@@ -57,9 +57,9 @@ static struct proc_dir_entry *pde_subdir_find(struct proc_dir_entry *dir,
 	struct rb_node *node = dir->subdir.rb_node;
 
 	while (node) {
-		struct proc_dir_entry *de = container_of(node,
-							 struct proc_dir_entry,
-							 subdir_node);
+		struct proc_dir_entry *de = rb_entry(node,
+						     struct proc_dir_entry,
+						     subdir_node);
 		int result = proc_match(len, name, de);
 
 		if (result < 0)
@@ -80,8 +80,9 @@ static bool pde_subdir_insert(struct proc_dir_entry *dir,
 
 	/* Figure out where to put new node */
 	while (*new) {
-		struct proc_dir_entry *this =
-			container_of(*new, struct proc_dir_entry, subdir_node);
+		struct proc_dir_entry *this = rb_entry(*new,
+						       struct proc_dir_entry,
+						       subdir_node);
 		int result = proc_match(de->namelen, de->name, this);
 
 		parent = *new;