selftest: replace qemu-kvm with one based on dracut's run-qemu
    
    Dracut's run-qemu could find  which virtualization technology to the
    user in the order of kvm, kqemu, userspace. Using run-qemu could allow
    running tests where qemu-kvm doesn't exist.
    
    Signed-off-by: Coiby Xu <coxu@redhat.com>
    Acked-by: Kairui Song <kasong@redhat.com>