Remove unused variable
Remove unused variable

bhermanmit/openmc,wbinventor/openmc,samuelshaner/openmc,johnnyliu27/openmc,walshjon/openmc,samuelshaner/openmc,shikhar413/openmc,shikhar413/openmc,smharper/openmc,paulromano/openmc,smharper/openmc,johnnyliu27/openmc,liangjg/openmc,paulromano/openmc,walshjon/openmc,wbinventor/openmc,amandalund/openmc,johnnyliu27/openmc,wbinventor/openmc,johnnyliu27/openmc,amandalund/openmc,wbinventor/openmc,walshjon/openmc,smharper/openmc,samuelshaner/openmc,shikhar413/openmc,liangjg/openmc,paulromano/openmc,amandalund/openmc,paulromano/openmc,shikhar413/openmc,amandalund/openmc,mit-crpg/openmc,mit-crpg/openmc,liangjg/openmc,samuelshaner/openmc,bhermanmit/openmc,walshjon/openmc,smharper/openmc,mit-crpg/openmc,liangjg/openmc,mit-crpg/openmc