Btrfs: properly set new buffers for new blocks up to date

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2818f1c..c86f0e6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -467,7 +467,7 @@
 		return NULL;
 	}
 	buf = find_tree_block(root, ins.objectid);
-	dirty_tree_block(trans, root, buf);
+	set_buffer_uptodate(buf);
 	return buf;
 }