fix drawing nodes without CPUs
fix drawing nodes without CPUs

This commit was SVN r191.

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