[ob] Rename NO_ERROR

Sat Feb 4 12:00:00 GMT 2006

> Date: Fri, 3 Feb 2006 16:51:46 -0500
> From: Daniel Jacobowitz <drow@false.org>
> 
> The Windows (at least mingw32's version) headers apparently define NO_ERROR.
> The least of several cretinous things I've learned about Windows programming
> in the last week.

Out of curiosity, what were the other cretinous things?  (Mail me
privately if you think the answer will not be interesting to others.)