Remove hwloc v1.9.

We switched to hwloc v1.9.1 at the end of August and testing has been
stable since, so remove v1.9 now.
Merge pull request #511 from gbtitus/rm-hwloc-1.9

Remove hwloc v1.9.

We switched to hwloc v1.9.1 at the end of August and testing has been
stable since, so remove v1.9 now.

Reviewed over email beforehand with Brad/Sung/Elliot.