kernel32/tests: Added last error tests for GetPrivateProfileString

[Paul Vriens]

Dmitry Kislyuk wrote:
> I don't have a particular app for you, however, there can easily be apps that would behave differently from how they would on Windows due to these last errors not being set to what the app expects. Do you have a reason why Wine behavior should not match the Windows behavior in these test cases? By Windows behavior I am referring to the more recent Windows versions of course.
> 
> 
> Dmitry
> 
Please bottom-post.

I don't think we want to have last errors set or tested just for the 
sake of it. I can imagine it makes some sense in a failure case (return 
value of GetPrivateProfileString being 0?).

Others, please correct me if I'm wrong here.

-- 
Cheers,

Paul.