Fixed calculational error in reflective boundary condition for general plane surface.
Fixed calculational error in reflective boundary condition for general plane surface.

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