examples: small update to mpi interop example
examples: small update to mpi interop example

StanfordLegion/legion,StanfordLegion/legion,sdalton1/legion,StanfordLegion/legion,sdalton1/legion,StanfordLegion/legion,sdalton1/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,sdalton1/legion,StanfordLegion/legion,sdalton1/legion,sdalton1/legion