dlls/comctl32/tests/tab.c: Transform CheckSize from a macro to a function.

[Nikolay Sivov]

Gerald Pfeifer wrote:
> This not only avoids a 12+ line macro, it also sheds a couple of
> compiler warnings with GCC 4.4 (though not the forthcoming 4.5).
>
> Gerald
>
>
> ChangeLog:
> Transform CheckSize from a macro to a function.
>   
Hi, Gerald.

This patch breaks line trace for tests. You should pass __LINE__ to your 
helper to work this as before.