usnic: minor cleanup / consolidation

CMR'ing just to (try to) keep the differences between trunk and v1.8
branch (somewhat) small.

Reviewed by Dave Goodell

cmr=v1.8.3:reviewer=ompi-rm1.8
usnic: revert r32315 because the BTL move to opal is ongoing

Let's not make the move to OPAL any harder than it has to be; this
commit can wait until after the BTL move.