md-cluster: choose correct label when clustered layout is not supported

r10conf is already successfully allocated before checking the layout

Signed-off-by: Lidong Zhong <lzhong@suse.com>
Reviewed-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <sh.li@alibaba-inc.com>