Merge branch 'compiler-warnings' of https://github.com/rudimeier/util-linux

* 'compiler-warnings' of https://github.com/rudimeier/util-linux:
  exec_shell: prevent basename from modifying env
  lib/path: ifdef path_set_prefix() like in path.h
  lib: fix unused parameters and variables
  misc: fix some printf format strings
  include: add missing includes
  ipcs:  ulong -> unsigned long
  libcommon: don't include sysinfo.h