OLE32/compobj: gcc 4.0 -Wpointer-sign fixes

[Mike McCormack]

Robert Shearman wrote:

> I don't think there is any need to split the function into two as you 
> can just use 'idstr' directly, instead of 's'. Also, note that this 
> function will soon be converted into using WCHARs, but I don't think 
> that should change anything.

One part of the function clearly validates the string, while the other 
part converts it.  There's two logically seperate parts, and splitting 
the function makes that clear.

Mike