Summary:
There is a corner case when using WriteUnprepared transactions when
`WriteUnpreparedTxn::Get` returns `Status::TryAgain` instead of
propagating the result of `GetFromBatchAndDB`. The patch adds
`PermitUncheckedError` to make the `ASSERT_STATUS_CHECKED` build pass in
this case as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8947
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D31125422
Pulled By: ltamasi
fbshipit-source-id: 42de51dcfa9384e032244c2b4d3f40e9a4111194
be206db351