The batman-adv kernel module we are using in OpenWrt hasn't been
compiled with debug log support, something I think we should definitely
have enabled in our first batch of nodes.
I can't remember who took the lead on our build server but can you try
to make this happen? How to compile with debug log support:
http://www.mjmwired.net/kernel/Documentation/networking/batman-adv.txt#187
-- rhodey