Fix swprintf call for _GLIBCXX_HAVE_BROKEN_VSWPRINTF

339ca50a57364b2509a6b5e7a073698038096a4d broke build with GCC for Windows for
code which was specific to windows. This should have never been mixed with
clang specific hacks.

Just split this call in a clang and a _GLIBCXX_HAVE_BROKEN_VSWPRINTF specific
implementation.