Fix fileno(get_pipe()) for MSVC
Fix fileno(get_pipe()) for MSVC

MSVC is unable to parse the code:
  fileno(get_pipe())
when directly as an argument for ppack() or punpack(). This may
be because fileno() is replaced with _fileno() in a #define.

tarruda/check,tarruda/check,tarruda/check,tarruda/check,tarruda/check