md/raid10: fix wrong setting of max_corr_read_errors

hulk inclusion
category: bugfix
bugzilla: 188290, https://gitee.com/openeuler/kernel/issues/I6ECBD


CVE: NA

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max_corr_read_errors should not be negative number. Change it to
unsigned int where use it.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>