hwloc_pid_t is unsigned on windows
hwloc_pid_t is unsigned on windows

This commit was SVN r2016.

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