Fix a bug where iterator can return incorrect data for DeleteRange() users (#11786)

Fix a bug where iterator can return incorrect data for DeleteRange() users (#11786)

Summary:
This should only affect iterator when
- user uses DeleteRange(),
- An iterator from level L has a non-ok status (such non-ok status may not be caught before the bug fix in https://github.com/facebook/rocksdb/pull/11783), and
- A range tombstone covers a key from level > L and triggers a reseek sets the status_ to OK in SeekImpl()/SeekPrevImpl() e.g. https://github.com/facebook/rocksdb/blob/bd6a8340c3a2db764620e90b3ac5be173fc68a0c/table/merging_iterator.cc#L801

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11786

Differential Revision: D48908830

Pulled By: cbi42

fbshipit-source-id: eb564be375af4e33dc27542eff753260186e6d5d