Summary:
Otherwise the build may report warning about missing
`benchmark.h` for some targets, the error won't break the build.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8523

Test Plan:
`make blackbox_ubsan_crash_test` on a machine without
benchmark lib installed.

Reviewed By: pdillinger

Differential Revision: D29682478

Pulled By: jay-zhuang

fbshipit-source-id: e1261fbcda46bc6bd3cd39b7b03b7f78927d0430