message: Fix fsync on Redox
diff: #include "test_helpers.h"
  int main(void) {
  - int fd = open(".", 0, 0);
  + int fd = open("example_dir/1-never-gonna-give-you-up", O_RDWR);
  ERROR_IF(open, fd, == -1);
  UNEXP_IF(open, fd, < 0);
  