Do not ever put I/O objects in levels (fixes lstopo --restrict with pci devices)
Do not ever put I/O objects in levels (fixes lstopo --restrict with pci devices)

git-svn-id: b45eb58a730bface9285fcfce17223741c32356f@3293 4b44e086-7f34-40ce-a3bd-00e031736276

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