Fix write_child_nodes macro to enable yaml output of navtree.

Change-Id: Ic9fffd7b088f51b930b52d261454be4c60cde6b0
diff --git a/res/assets/templates/yaml_navtree.cs b/res/assets/templates/yaml_navtree.cs
index d3f8d31..74eb2af 100644
--- a/res/assets/templates/yaml_navtree.cs
+++ b/res/assets/templates/yaml_navtree.cs
@@ -18,7 +18,7 @@
 <?cs var:whitespace ?>    path: <?cs var:child.link ?><?cs
     if:subcount(child.children) ?>
 <?cs var:whitespace ?>    section:<?cs
-    call:write_child_nodes(child) ?><?cs
+    call:write_child_nodes(child,"  ", 0) ?><?cs
     /if ?><?cs
     /each ?><?cs
 /def ?><?cs