Notify user when oscap_source_validate failed.
Notify user when oscap_source_validate failed.

This will allow us to drop validation_failed and _validation_failed
functions.

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