When docker starts, build a used/free Device Id map from the per device meta files we already have. These meta files have the data which device Ids are in use. Parse these files and mark device as used in the map. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Upstream-commit: 39dc7829dea87d4be8e6e9b2a598fb354ebf4ba0 Component: engine