Failed mount does not lead to startup error

[Klaas-]

Hi,
I think the services created by docker-storage-setup need to enforce successful startup. In my case the /var/lib/docker mount had gone into a bad state ("mount: wrong fs type, bad option, bad superblock") but that did not keep docker from starting and using my /var volume directly.

I think the unit files need to be changed like this:
https://github.com/projectatomic/container-storage-setup/blob/master/container-storage-setup.sh#L1330
needs to be RequiredBy=

And https://github.com/projectatomic/container-storage-setup/blob/master/docker-storage-setup.service#L12
needs to also have RequiredBy=docker.service

That way an admin is sure to notice a problem with docker storage.

I'll create a PR.

Greetings
Klaas