!8106 usb: dwc3: ep0: fix NULL pointer exception

Merge Pull Request from: @ci-robot 
 
PR sync from: Zheng Yejian <zhengyejian1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/C4VLPJUQU6KKC6MIBPJ2SB22ZBTXEUFP/ 
 
https://gitee.com/src-openeuler/kernel/issues/I9R4C8 
 
Link:https://gitee.com/openeuler/kernel/pulls/8106

 

Reviewed-by: Liu YongQiang <liuyongqiang13@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>