md/raid1-10: factor out a helper to submit normal write

mainline inclusion
from mainline-v6.5-rc1
commit 8295efbe
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I8UKFJ
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8295efbe68c080047e98d9c0eb5cb933b238a8cb



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There are multiple places to do the same thing, factor out a helper to
prevent redundant code, and the helper will be used in following patch
as well.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529131106.2123367-4-yukuai1@huaweicloud.com



Conflicts:
  Commit 309dca30 ("block: store a block_device pointer in struct bio")
  changed "mbio->bi_disk" to "mbio->bi_bdev";
  Commit 70200574 ("block: remove QUEUE_FLAG_DISCARD") use a non-zero
  max_discard_sectors as an indicator for discard support.
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>