Fixes failure on RemoveDevice when host is AUFS, and running devicemapper test docker-in-docker https://gist.github.com/tonistiigi/59559cbfb3f2df26b29c Signed-off-by: Vincent Batts <vbatts@redhat.com> Upstream-commit: c9a76622086cf6019b3ec71ae53fc71c0396a1ef Component: engine