dm verity: allow only one error handling mode

mainline inclusion
from mainline-v5.13-rc1
commit 219a9b5e
category: bugfix
bugzilla: 51874
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=219a9b5e738b75a6a5e9effe1d72f60037a2f131



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If more than one one handling mode is requested during DM verity table
load, the last requested mode will be used.

Change this to impose more strict checking so that the table load will
fail if more than one error handling mode is requested.

Signed-off-by: JeongHyeon Lee <jhs2.lee@samsung.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Reviewed-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>