src/pcp/atop/atopsar.c: fix coverity CID 288176 Division or modulo by float zero
src/pcp/atop/atopsar.c: fix coverity CID 288176 Division or modulo by float zero

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp