Enable write rate limit for updaterandom benchmark

Summary:
We have FLAGS_benchmark_write_rate_limit to limit write rate in
db_bench, but it was not in use for updaterandom benchmark.
Closes https://github.com/facebook/rocksdb/pull/2578

Differential Revision: D5420328

Pulled By: yiwu-arbug

fbshipit-source-id: 5fa48c2b88f2f2dc83d615cb9c40c472bc916835

tools/db_bench_tool.cc

@@ -489,7 +489,8 @@ static bool ValidateCacheNumshardbits(const char* flagname, int32_t value) {
   return true;
 }
 
-DEFINE_bool(verify_checksum, true, "Verify checksum for every block read"
+DEFINE_bool(verify_checksum, true,
+            "Verify checksum for every block read"
             " from storage");
 
 DEFINE_bool(statistics, false, "Database statistics");
@@ -4592,6 +4593,12 @@ void VerifyDBFromDB(std::string& truth_db_name) {
         abort();
       }
 
+      if (thread->shared->write_rate_limiter) {
+        thread->shared->write_rate_limiter->Request(
+            key.size() + value_size_, Env::IO_HIGH, nullptr /*stats*/,
+            RateLimiter::OpType::kWrite);
+      }
+
       Status s = db->Put(write_options_, key, gen.Generate(value_size_));
       if (!s.ok()) {
         fprintf(stderr, "put error: %s\n", s.ToString().c_str());