hwloc: commit minor bug fix from hwloc git

Bring down 3aa0ed6 from the hwloc v1.7 branch: Stevens says we should
GETFD before we SETFD, so we do

cmr=v1.8.2:reviewer=rhc
Use the correct abstraction layer name for the data dirs
Flush the show_help system on our way out - this also restores the opal_show_help function pointer to the OPAL layer for any subsequent processing.

cmr=v1.8.2:reviewer=jsquyres