Fix jit-serialize future time check

Summary:
On filesystems with 1s file time resolution, `hphp/test/run --jit-serialize`
was failing, reporting lots of tests had profiles from the future.

Reviewed By: binliu19

Differential Revision: D13186363

fbshipit-source-id: 87dd0e0d075bb22abdb1c6710d17e14a6c429f66

hphp/runtime/vm/jit/prof-data-serialize.cpp

@@ -1345,7 +1345,7 @@ std::string deserializeProfData(const std::string& filename, int numWorkers) {
    if (buildTime <= currTime - 3600 * RuntimeOption::ProfDataTTLHours) {
      throw std::runtime_error(
          "Stale profile data (check Eval.ProfDataTTLHours)");
    } else if (buildTime >= currTime) {
    } else if (buildTime > currTime) {
      throw std::runtime_error("profile data dumped in the future?");
    }
    ProfDataDeserializer::s_buildTime = buildTime;