RtlAtom tests improved

[György 'Nog' Jeney]

> I figured out that the RtlCreateAtomTable function as expecting to get
> passed in a NULL as the initial Table, otherwise it thinks that the
> argument is a valid atom table and just returns success.  This
> unfourtuneatly makes the test
> results that Dimitrie send useless because RtlCreateAtomTable thought
               ^^^^^^^^
I realy did mean Dimitry.

> that the
> table was valid but all the other functions realised that it wasn't.
> Could someone please rerun these tests on an nt system again?
>
> ChangeLog:
>  * dlls/ntdll/tests/Makefile.in
>  * dlls/ntdll/tests/atom.c
>    Add tests for RtlAtom functions.
>
> nog.