Summary:
We had miscalculated (not sure if I suddenly can’t count, or if there is something else going on), and need to leave more overhead to get the benchmarks to run reliably under 1 hour.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11189

Reviewed By: cbi42

Differential Revision: D43052045

Pulled By: ajkr

fbshipit-source-id: 3fe68432ed76a1f87d34129b0246e6b6a70a49f2