fs/jffs2: use rbtree postorder iteration helper instead of opencoding

Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead
of opencoding an alternate postorder iteration that modifies the tree

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c
index ae81b01..386303d 100644
--- a/fs/jffs2/readinode.c
+++ b/fs/jffs2/readinode.c
@@ -543,33 +543,13 @@
 
 static void jffs2_free_tmp_dnode_info_list(struct rb_root *list)
 {
-	struct rb_node *this;
-	struct jffs2_tmp_dnode_info *tn;
+	struct jffs2_tmp_dnode_info *tn, *next;
 
-	this = list->rb_node;
-
-	/* Now at bottom of tree */
-	while (this) {
-		if (this->rb_left)
-			this = this->rb_left;
-		else if (this->rb_right)
-			this = this->rb_right;
-		else {
-			tn = rb_entry(this, struct jffs2_tmp_dnode_info, rb);
+	rbtree_postorder_for_each_entry_safe(tn, next, list, rb) {
 			jffs2_free_full_dnode(tn->fn);
 			jffs2_free_tmp_dnode_info(tn);
-
-			this = rb_parent(this);
-			if (!this)
-				break;
-
-			if (this->rb_left == &tn->rb)
-				this->rb_left = NULL;
-			else if (this->rb_right == &tn->rb)
-				this->rb_right = NULL;
-			else BUG();
-		}
 	}
+
 	*list = RB_ROOT;
 }