Stop printing after verification fails (#5493)

Summary:
Stop verification and printing once verification fails.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5493

Differential Revision: D15928992

Pulled By: riversand963

fbshipit-source-id: 699feac034a217d57280aa3fb50f5aba06adf317

tools/db_stress.cc

@@ -4054,6 +4054,9 @@ class AtomicFlushStressTest : public StressTest {
     assert(num == iters.size());
     std::vector<Status> statuses(num, Status::OK());
     do {
+      if (shared->HasVerificationFailedYet()) {
+        break;
+      }
       size_t valid_cnt = 0;
       size_t idx = 0;
       for (auto& iter : iters) {