Make sure beginning/ending cousin links are NULL even after restrict
Make sure beginning/ending cousin links are NULL even after restrict

(needs backport in v1.2 and v1.3)

git-svn-id: 14be032f8f42541b1a281b51ae8ea69814daf20e@3653 4b44e086-7f34-40ce-a3bd-00e031736276

BlueBrain/hwloc,BlueBrain/hwloc,BlueBrain/hwloc,BlueBrain/hwloc