shell32: add SHCreateSessionKey stub

[Nikolay Sivov]

On 28.12.2015 8:15, Austin English wrote:
> +HRESULT WINAPI SHCreateSessionKey(REGSAM access, HKEY *hkey)
> +{
> +        FIXME("stub: %d %p\n", access, hkey);
> +        return ERROR_SUCCESS;
> +}

This is wrong regarding tracing format, return value and formatting.
I'll try to find time this week to send an actual implementation. It's
fine to have fixed stub in before that of course.