radi10: fix leak of 'r10bio->remaining' for recovery

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6JZ3F


CVE: NA

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raid10_sync_request() will add 'r10bio->remaining' for both rdev and
replacement rdev. However, if the read io failed,
recovery_request_write() will return without issuring the write io, in
this case, end_sync_request() is only called once and 'remaining' is
leaked, which will cause io hang.

Fix the probleming by decreasing 'remaining' according to if 'bio' and
'repl_bio' is valid.

Fixes: 24afd80d ("md/raid10: handle recovery of replacement devices.")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>