!1428 scsi: iscsi_tcp: Check that sock is valid before iscsi_set_param()

Merge Pull Request from: @ci-robot 
 
PR sync from: Zhong Jinghua <zhongjinghua@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/2Q2MUBDGYX4ZZCIKBMR4GVCYTRF6GIG7/ 
 
https://gitee.com/openeuler/kernel/issues/I7L8DZ?from=project-issue 
 
Link:https://gitee.com/openeuler/kernel/pulls/1428

 

Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>