block, bfq: move forward the getting of an extra ref in bfq_bfqq_move

mainline inclusion
from mainline-5.7-rc1
commit fd1bb3ae
category: bugfix
bugzilla: 50775
CVE: NA

---------------------------

Commit ecedd3d7 ("block, bfq: get extra ref to prevent a queue
from being freed during a group move") gets an extra reference to a
bfq_queue before possibly deactivating it (temporarily), in
bfq_bfqq_move(). This prevents the bfq_queue from disappearing before
being reactivated in its new group.

Yet, the bfq_queue may also be expired (i.e., its service may be
stopped) before the bfq_queue is deactivated. And also an expiration
may lead to a premature freeing. This commit fixes this issue by
simply moving forward the getting of the extra reference already
introduced by commit ecedd3d7 ("block, bfq: get extra ref to
prevent a queue from being freed during a group move").

Reported-by:  <cki-project@redhat.com>
Tested-by:  <cki-project@redhat.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>