db_stress print hex key for MultiGet() inconsistency (#9324)

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/9324

Reviewed By: riversand963

Differential Revision: D33248178

Pulled By: ajkr

fbshipit-source-id: c8a7382ed613f9ac3a0a2e3fa7d3c6fe9c95ef85

db_stress_tool/batched_ops_stress.cc

@@ -232,7 +232,8 @@ class BatchedOpsStressTest : public StressTest {
       for (size_t i = 1; i < num_prefixes; i++) {
         if (values[i] != values[0]) {
           fprintf(stderr, "error : inconsistent values for key %s: %s, %s\n",
-                  key_str[i].c_str(), StringToHex(values[0].ToString()).c_str(),
+                  StringToHex(key_str[i]).c_str(),
+                  StringToHex(values[0].ToString()).c_str(),
                   StringToHex(values[i].ToString()).c_str());
           // we continue after error rather than exiting so that we can
           // find more errors if any