Fix oscap_buffer_free for NULL parameter
Fix oscap_buffer_free for NULL parameter

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