While u64_stats_fetch_retry is only preempt_disable on 32bit
UP system. This is not enough to avoid preemption by bh and
may read strange 64 bit value.
Signed-off-by: NHong Zhiguo <zhiguohong@tencent.com>
Acked-by: NTejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: NJens Axboe <axboe@kernel.dk>