[probes] oval_fts: fix traversal for nil filename
[probes] oval_fts: fix traversal for nil filename

OpenSCAP/openscap,openprivacy/openscap,isimluk/openscap,postfix/openscap,ybznek/openscap,postfix/openscap,ybznek/openscap,jan-cerny/openscap,ybznek/openscap,postfix/openscap,redhatrises/openscap,mpreisler/openscap,isimluk/openscap,openprivacy/openscap,mpreisler/openscap,OpenSCAP/openscap,Hexadorsimal/openscap,openprivacy/openscap,redhatrises/openscap,ybznek/openscap,postfix/openscap,jan-cerny/openscap,Hexadorsimal/openscap,Hexadorsimal/openscap,jan-cerny/openscap,Hexadorsimal/openscap,redhatrises/openscap,postfix/openscap,mpreisler/openscap,redhatrises/openscap,mpreisler/openscap,openprivacy/openscap,OpenSCAP/openscap,mpreisler/openscap,openprivacy/openscap,ybznek/openscap,isimluk/openscap,jan-cerny/openscap,mpreisler/openscap,redhatrises/openscap,OpenSCAP/openscap,OpenSCAP/openscap,Hexadorsimal/openscap,openprivacy/openscap,redhatrises/openscap,jan-cerny/openscap,postfix/openscap,isimluk/openscap,Hexadorsimal/openscap,OpenSCAP/openscap,jan-cerny/openscap,isimluk/openscap,isimluk/openscap,ybznek/openscap