v3.1.x: btl/vader: move memory barrier to where it belongs#5541

bwbarrett merged 1 commit intoopen-mpi:v3.1.xopen-mpi/ompi:v3.1.xfrom

jsquyres:pr/v3.1.x/vader-fixjsquyres/ompi:pr/v3.1.x/vader-fixCopy head branch name to clipboard