libct/cg/fs.Set: fix error message

There is no point in showing the underlying error when path == "",
because it is ENOENT.

Revert the change done in commit e158483.

Fixes: e158483
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

libcontainer/cgroups/fs/fs.go

@@ -191,7 +191,7 @@ func (m *Manager) Set(r *configs.Resources) error {
 			if path == "" {
 				// We never created a path for this cgroup, so we cannot set
 				// limits for it (though we have already tried at this point).
-				return fmt.Errorf("cannot set %s limit: container could not join or create cgroup, and the error is %w", sys.Name(), err)
+				return fmt.Errorf("cannot set %s limit: container could not join or create cgroup", sys.Name())
 			}
 			return err
 		}