There is no exact way how to figure out whether BPF devices support is
compiled into kernel.  One way is to check kernel configure options but
this is not reliable as it may not be available.  Let's try to do
syscall to which will list BPF cgroup device programs.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>