Fix db_bench

Summary: Fix simple issue with FLAGS_simcache_size condition

Test Plan: run db_bench

Reviewers: lightmark

Reviewed By: lightmark

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58743

tools/db_bench_tool.cc

@@ -2117,7 +2117,7 @@ class Benchmark {
     if (FLAGS_statistics) {
       fprintf(stdout, "STATISTICS:\n%s\n", dbstats->ToString().c_str());
     }
-    if (FLAGS_simcache_size) {
+    if (FLAGS_simcache_size >= 0) {
       fprintf(stdout, "SIMULATOR CACHE STATISTICS:\n%s\n",
               std::dynamic_pointer_cast<SimCache>(cache_)->ToString().c_str());
     }