Summary:
When the --try_load_options is used in conjunction with the
--column_family option, ldb incorrectly sets the ColumnFamilyOptions for
that column family to defaults. This PR fixes that by retaining from the
OPTIONS file and applying command line overrides.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7847
Test Plan: Add a unit test in ldb_cmd_test
Reviewed By: ajkr
Differential Revision: D25874720
Pulled By: anand1976
fbshipit-source-id: 04bcf23b55e5a30b5b6a59b0e5cb4faef3da7429