!3072 printk: ringbuffer: Fix truncating buffer size min_t cast

Merge Pull Request from: @ci-robot 
 
PR sync from: Ye Weihua <yeweihua4@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/LKHL2IVY56IYQPXWBXD5ZDMPMLCE76M7/ 
 
https://gitee.com/openeuler/kernel/issues/I8KG4V 
 
Link:https://gitee.com/openeuler/kernel/pulls/3072

 

Reviewed-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>