Summary:
This test frequently times out under TSAN; parallelizing it should fix
this issue.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5632

Test Plan:
make check
buck test mode/dev-tsan internal_repo_rocksdb/repo:db_bloom_filter_test

Differential Revision: D16519399

Pulled By: ltamasi

fbshipit-source-id: 66e05a644d6f79c6d544255ffcf6de195d2d62fe