Merge branch 'lsfd--tty' of https://github.com/masatake/util-linux

Merge branch 'lsfd--tty' of https://github.com/masatake/util-linux

* 'lsfd--tty' of https://github.com/masatake/util-linux:
  tests: (lsfd) add a case testing NAME, SOURCE, ENDPOINTS, and PTMX.TTY-INDEX columns of pts fds
  tests: (test_mkfds::pty) add a new factory
  lsfd: fill ENDPOINTS column for pty devices
  lsfd: add attach_xinfo and get_ipc_class methods to cdev_ops
  lsfd: add PTMX.TTY-INDEX column
  lsfd: utilize /proc/tty/drivers for filling SOURCE column of tty devices
  lsfd: make the order of calling finalize_* and initialize_* consistent