COMCTL32: Fix InitCommonControlsEx prototype

[Thomas Weidenmueller]

Mike McCormack wrote:
> The version of the Windows Platform SDK that I'm looking at agrees
> with Wine.
This is how it is defined in the latest public platform SDK (Windows SDK
v6.0).
> There is also no reason to make a pointless change to the name of the
> argument, so this patch looks pointless and wrong to me.
While the name of the parameter is irrelevant, I picked the one used in
the PSDK definition to make the implementation more readable when using
the latest PSDK documentation.

- Thomas