oval fts: check errno after calls to fts_open()
oval fts: check errno after calls to fts_open()

comparing the result to NULL is not enough

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