kernel32: Correct WideCharToMultiByte and MultiByteToWideChar error codes and conditions

[Alex Henrie]

2012/5/10 Nikolay Sivov <bunglehead at gmail.com>:
>> Which file should I have used?
>
> codepage.c, you could search all test files for a thing you're trying to
> add.

Okay, I've moved the tests to codepage.c in try 4. Thanks for the tip,
I'll keep that in mind from now on.

> Nothing really changed in try3, test helpers names are still meaningless.

Well, what should I name them?

> Also you'll be probably asked to split this, cause your changes are
> independent - validation of input parameters and flags handling are separate
> fixes.

In this case, we're just validating that flags is 0, which is the same
idea as the other parameter checks, so it should be fine.