md/raid10: factor out code from wait_barrier() to stop_waiting_barrier()

mainline inclusion
from mainline-v6.1-rc1
commit ed2e063f
category: bugfix
bugzilla: 188380, https://gitee.com/openeuler/kernel/issues/I6GISC
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=ed2e063f92c44c891ccd883e289dde6ca870edcc



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

Currently the nasty condition in wait_barrier() is hard to read. This
patch factors out the condition into a function.

There are no functional changes.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>

conflict:
	drivers/md/raid10.c

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>