!4706 mtd: Fix gluebi NULL pointer dereference caused by ftl notifier

Merge Pull Request from: @ci-robot 
 
PR sync from: ZhaoLong Wang <wangzhaolong1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/U3SBZFZ636UQMC6OEWCAHRMLXASBQA7G/ 
 
https://gitee.com/src-openeuler/kernel/issues/I932W5 
 
Link:https://gitee.com/openeuler/kernel/pulls/4706

 

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