net: hns3: fix use-after-free bug in hclgevf_send_mbx_msg

net: hns3: fix use-after-free bug in hclgevf_send_mbx_msg

[ Upstream commit 27cbf64a766e86f068ce6214f04c00ceb4db1af4 ]

Currently, the hns3_remove function firstly uninstall client instance,
and then uninstall acceletion engine device. The netdevice is freed in
client instance uninstall process, but acceletion engine device uninstall
process still use it to trace runtime information. This causes a use after
free problem.

So fixes it by check the instance register state to avoid use after free.

Fixes: d8355240cf8f ("net: hns3: add trace event support for PF/VF mailbox")
Signed-off-by: Jie Wang <wangjie125@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>