also detect when CPU_SETSIZE didn't get defined
also detect when CPU_SETSIZE didn't get defined

This commit was SVN r3181.

shekkbuilder/hwloc,ggouaillardet/hwloc,ggouaillardet/hwloc,ggouaillardet/hwloc,shekkbuilder/hwloc,shekkbuilder/hwloc,ggouaillardet/hwloc,shekkbuilder/hwloc