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

* 'lsfd--btrfs' of https://github.com/masatake/util-linux:
  tests: (lsfd::mkfds-inotify-btrfs) test INOTIFY.INODES cooked output
  lsfd: extend nodev table to decode "btrfs" on SOURCE column
  lsfd: (refactor) rename a member of struct proc
  lsfd: (refactor) rename a local variable and a parameter
  lsfd: (refactor) split the function processing mountinfo file
  lsfd: (refactor) store a mnt_namespace object to struct process
  lsfd: (refactor) use a binary tree as the implementation for mnt_namespaces
  lsfd: read /proc/$pid/ns/mnt earlier
  lsfd: (refactor) rename add_nodevs to read_mountinfo
  lsfd: make the way to read /proc/$pid/mountinfo robust
  lsfd: (cosmetic) normalize whitespaces