constant signed/unsigned comparison warning

[Chip Salzenberg]

According to Per Bothner:
>   if (i < 0) {
> 	...
>   }
>   else if (i < sizeof(foo)) {
> 	...
>   }

But that's not correct.  If you're writing INT_MAX + 1 bytes, then the
return value is INT_MIN, and that's an indication of success.
-- 
Chip Salzenberg          - a.k.a. -           <chip@pobox.com>
 (Roller coaster on camera:)  "Wow, this square quarter mile
    has unbelievably good light rail transit!"  // MST3K