Use vmlinux.h from kernel-devel
    
    Let's make sure we use the vmlinux.h from kernel-devel or none at
    all. This makes sure the systemd BPF programs are built against a
    known version of vmlinux.h and we don't depend on /sys being available
    to generate vmlinux.h ourselves.
    
    Use rpmdev-vercmp to select vmlinux.h from the latest kernel.