console.c: remove old ifdef

* ext/io/console/console.c (LAST_ERROR): remove old ifdef, should
  use rb_w32_map_errno always.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50419 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/io/console/console.c

@@ -50,11 +50,7 @@ typedef struct sgttyb conmode;
 #include <winioctl.h>
 typedef DWORD conmode;
 
-#ifdef HAVE_RB_W32_MAP_ERRNO
 #define LAST_ERROR rb_w32_map_errno(GetLastError())
-#else
-#define LAST_ERROR EBADF
-#endif
 #define SET_LAST_ERROR (errno = LAST_ERROR, 0)
 
 static int