Remove dependence of sab_scatter on particle.
Remove dependence of sab_scatter on particle.

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