Ensure start is 0 on rank 0 after MPI_EXSCAN.
Ensure start is 0 on rank 0 after MPI_EXSCAN.

walshjon/openmc,shenqicang/openmc,smharper/openmc,kellyrowland/openmc,keadyk/openmc_mg_prepush,smharper/openmc,mit-crpg/openmc,walshjon/openmc,bhermanmit/cdash,smharper/openmc,lilulu/openmc,sxds/opemmc,nhorelik/openmc,mjlong/openmc,wbinventor/openmc,shikhar413/openmc,wbinventor/openmc,shenqicang/openmc,amandalund/openmc,paulromano/openmc,liangjg/openmc,amandalund/openmc,wbinventor/openmc,bhermanmit/openmc,kellyrowland/openmc,shikhar413/openmc,paulromano/openmc,mjlong/openmc,shikhar413/openmc,mit-crpg/openmc,smharper/openmc,sxds/opemmc,paulromano/openmc,shikhar413/openmc,liangjg/openmc,wbinventor/openmc,lilulu/openmc,paulromano/openmc,liangjg/openmc,amandalund/openmc,nhorelik/openmc,keadyk/openmc_mg_prepush,samuelshaner/openmc,samuelshaner/openmc,bhermanmit/openmc,walshjon/openmc,samuelshaner/openmc,walshjon/openmc,lilulu/openmc,mit-crpg/openmc,amandalund/openmc,keadyk/openmc_mg_prepush,liangjg/openmc,mit-crpg/openmc,johnnyliu27/openmc,johnnyliu27/openmc,johnnyliu27/openmc,johnnyliu27/openmc,samuelshaner/openmc