[RFC] Fix various compiler warning

[Carmelo AMOROSO]

Hans-Christian Egtvedt wrote:
> On Mon, 3 Nov 2008 17:35:47 -0500
> Rob Landley <rob at landley.net> wrote:
[SNIP]
> 
> There are more defines to be cleaned up I think, places where #if is
> used when I think it should really have been #ifdef.
> 
It depends on how this is used.
In a simple case just changing #if to #ifdef is correct and enough,
in other case it should be done as:

#if defined XXX && XXX
if we want also check that XXX is not defined 0

but this depends on how the macro is used and its meaning.

Cheers,
Carmelo

[SNIP]