We want them to run in sequence. For example we want mounts to be done (done by
`pkg/runc/etc/init.d/010-onboot`) before we start services (done by
`pkg/containerd/etc/init.d/020-containerd`). This was most likely introduced by
28b4245b12 ("Move onboot startup script to runc package").
None of the initscripts in pkg/* block, but some in projects (selinux and
logging, not updated here) do.
Signed-off-by: Ian Campbell <ijc@docker.com>