Merge branch 'fix/consolidate_validate_pfd_ino' of https://github.com/cgoesche/util...

* 'fix/consolidate_validate_pfd_ino' of https://github.com/cgoesche/util-linux-fork:
  lib: (pidutils.c) use uint64_t instead of ino_t for seamless cross-compatibility
  kill: use uint64_t as type for kill_control->pidfd_ino
  lib: (pidfd-utils.c) remove extraneous _GNU_SOURCE feature test macro
  lib: (pidfd-utils) new helper function to retrieve pidfd inode number
  lib: (pidfd-utils.c) add a helper routine to check the pidfd fs type
  kill: replace USE_KILL_WITH_PIDFD_INO ifdef with USE_PIDFD_INO_SUPPORT
  include: (pidfd-utils.h) conditionally define pidfd inode support
  libmount: add pidfs magic number for fstype check
  include: (statfs_magic.h) add pidfs magic number
  kill: use ul_get_valid_pidfd_or_err() to validate user provided pidfd inodes
  include: add helper routines for opening and validating pidfds

diff --cc libmount/src/utils.c
Simple merge