Dismantle cgyard in non-detached restore mode.

If the --restore-detached command line option is not specified during
restore, CRIU should unmount and remove the temporary cgyard directory
tree before waiting for the restored process to exit.  Otherwise, all
the temporary cgyard mount points will remain mounted and visible.
Signed-off-by: Saied Kazemi <saied@google.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-restore.c

@@ -1845,8 +1845,10 @@ static int restore_root_task(struct pstree_item *init)
 
 	write_stats(RESTORE_STATS);
 
-	if (!opts.restore_detach && !opts.exec_cmd)
+	if (!opts.restore_detach && !opts.exec_cmd) {
+		fini_cgroup();
 		wait(NULL);
+	}
 
 	return 0;