Merge branch 'list-columns-options' of https://github.com/masatake/util-linux

* 'list-columns-options' of https://github.com/masatake/util-linux:
  lslocks: add -H option printing avaiable columns
  lslocks: (refactor) add a helper function returning JSON type for a given column
  lslocks: (fix) set JSON type for COL_SIZE even when --bytes is specified
  lsfd: use helper functions in column-list-table.h
  add helper functions for implementing -H/--list-columns option