Restore txn kv fails and reports ErrRestoreInvalidRange

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Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. create a pure txn cluster(1 tikv, 1 pd)
2. rand generate txn data.
3. backup txn
4. restore txn

repeat above steps several times.

2. What did you expect to see? (Required)

restore txn always success.

3. What did you see instead (Required)

sometimes failed and reported
[BR:Restore:ErrRestoreInvalidRange]invalid restore range\n startKey > endKey xxx

4. What is your TiDB version? (Required)

master