Summary:
In CompactionIterator code, there are multiple places where the process
will abort in dbg mode before logging the error message describing the
cause. This PR changes only the logging behavior for compaction iterator so
that error message is written to LOG before the process aborts in debug
mode.

Also updated the triggering condition for an assertion for single delete with
user-defined timestamp.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10183

Test Plan: make check

Reviewed By: akankshamahajan15

Differential Revision: D37190218

Pulled By: riversand963

fbshipit-source-id: 741bb007067be7cfbe94ac9e530ad4b2b339c009