runc: remove call to libcontainer.Cgroupfs()
runc: remove call to libcontainer.Cgroupfs()

libcontainer.New() by default will call Cgroupfs() for enforcing a native
cgroup manager. Runc don't have to do that again.

Signed-off-by: WANG Chao <9a17315ee3bbc9b10e8ee11405e71349370d3653@gmail.com>

wcwxyz/runc,wcwxyz/runc,wcwxyz/runc