dinput: Fix name clashes (Resend #2)

[Andrew Talbot]

Alexandre Julliard wrote:

> Static is for variables, not for types. Types are local to the file they
> are declared in, that's why you need header files when you want to share
> type declarations.
> 

Ah, yes. It seems that only objects (i.e., named regions of storage) and
functions with external linkage can be accessible throughout the whole
program (or dll, in this case). And a structure tag is merely an identifier
not an object.

Thanks,

-- 
Andy.