fix if's that are followed by semicolons

[Mike McCormack]

Andreas Mohr wrote:

> Could you perhaps create a first version of a shell script tools/find_gotchas ?

I have other things to do at the moment, so go ahead if you're feeling 
motivated.  I suspect you'll run into alot of false positives.  There 
might be a compiler switch to turn on warnings for these things too (ie. 
statements with no effect).

Mike