commit 56f77d5ade
added support for cpu-rt-period and cpu-rt-runtime,
but always initialized the cgroup path, even if not
used.
As a result, containers failed to start on a
read-only filesystem.
This patch only creates the cgroup path if
one of these options is set.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit f285d5b3e8)
Signed-off-by: Victor Vieux <vieux@docker.com>