* src/lxc/lxc_container.c src/lxc/lxc_controller.c src/lxc/lxc_driver.c
  src/network/bridge_driver.c src/qemu/qemu_driver.c
  src/uml/uml_driver.c: virFileMakePath returns 0 for success, or the
  value of errno on failure, so error checking should be to test
  if non-zero, not if lower than 0