Cleanup existing controllers when cleanup fails mid-way.

Docker-DCO-1.1-Signed-off-by: Rohit Jnagal <jnagal@google.com> (github: rjnagal)

cgroups/fs/apply_raw.go

@@ -67,6 +67,7 @@ func Apply(c *cgroups.Cgroup, pid int) (cgroups.ActiveCgroup, error) {
 	}
 	for _, sys := range subsystems {
 		if err := sys.Set(d); err != nil {
+			d.Cleanup()
 			return nil, err
 		}
 	}