When paths are set, we only need to place the PID into proper
cgroups, and we do know all the paths already.
Both fs/d.path() and systemd/v1/getSubsystemPath() parse
/proc/self/mountinfo, and the only reason they are used
here is to check whether the subsystem is available.
Use a much simpler/faster check instead.
Frankly, I am not sure why the check is needed at all. Maybe it should
be dropped.
Also, for fs driver, since d is no longer used in this code path,
move its initialization to after it.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin
fad92bbffa