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

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

* 'lsfd-ipc-fifo' of https://github.com/masatake/util-linux:
  test: (lsfd) add a case for testing ENDPOINTS column of FIFOs
  test: (lsfd) extend test_mkfds to manage optional file descriptors
  lsfd: fill ENDPOINTS column for FIFOs
  lsfd: add ENDPOINTS column
  lsfd: move xstrappend and xstrputc to lsfd.h
  lsfd: add basic code for tracking IPC endpoints
  lsfd: add static modifier to nodev_table
  lsfd: delete __unused__ attribute for an used parameter