use variadic arguments in DEFINE_GUID also for MSVC (#374)

use variadic arguments in DEFINE_GUID also for MSVC (#374)

The fix for DEFINE_GUID that was recently added in pa_win_wdmks.c is also needed for the MSVC compiler.
Latest versions of the compiler support the /Zc:preprocessor option which is conforming to C99 and later standards
https://docs.microsoft.com/en-us/cpp/build/reference/zc-preprocessor?view=msvc-160
so it generates the exact same error as Clang (too many arguments error).

Co-authored-by: John Melas <john@jmelas.gr>