Add OSCAP_HIDDEN macros to oscap_buffer.h
Add OSCAP_HIDDEN macros to oscap_buffer.h

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