Merge branch 'lsfd--revise-unix-endpoints' of https://github.com/masatake/util-linux

Merge branch 'lsfd--revise-unix-endpoints' of https://github.com/masatake/util-linux

* 'lsfd--revise-unix-endpoints' of https://github.com/masatake/util-linux:
  lsfd: (man) fix a typo
  lsfd: add UNIX.IPEER column
  lsfd: fill ENDPOINTS column for UNIX one-way sockets
  include/list: add a macro for initializing list_head a declarative way
  lsfd: (refactor) add a helper function building ENDPOINTS strings for UNIX socket
  lsfd: add a dummy entry for UNIX socket having no peer to the IPC table
  tests: (lsfd::mkfds-unix-dgram, refactor) split the test into subtests
  tests: add ts_is_in_docker as a helper function
  lsfd: (man) fix a typo