Get rid of unused read_source routine in state_point module
Get rid of unused read_source routine in state_point module

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