!10033 ipv6: prevent possible NULL dereference in rt6_probe()

Merge Pull Request from: @ci-robot 
 
PR sync from: Zhengchao Shao <shaozhengchao@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/BI2UU7ALOT543XSMXYJ5AF7H2L6Y3EPT/ 
 
https://gitee.com/src-openeuler/kernel/issues/IACS4Q 
 
Link:https://gitee.com/openeuler/kernel/pulls/10033

 

Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>