Fixed error on do loop indices.
Fixed error on do loop indices.

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