[mdadm/f18] (2 commits) ...Only run make install-systemd on F18 and higher

[Jes Sorensen]

Summary of changes:

  7da68c8... Cleanup .spec file handling of different Fedora versions (*)
  0a98c0e... Only run make install-systemd on F18 and higher (*)

(*) This commit already existed in another branch; no separate mail sent