Btrfs: Fix extent_buffer and extent_state leaks

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index aed0861..5262b28 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -303,8 +303,8 @@
 	struct radix_tree_root pinned_radix;
 	struct radix_tree_root block_group_radix;
 	struct radix_tree_root block_group_data_radix;
-	struct radix_tree_root extent_map_radix;
 	struct radix_tree_root extent_ins_radix;
+	struct extent_map_tree free_space_cache;
 	u64 generation;
 	u64 last_trans_committed;
 	struct btrfs_transaction *running_transaction;