performance_tests: don't override log level to 0

tests/performance_tests/main.cpp

@@ -63,7 +63,6 @@ int main(int argc, char** argv)
   set_thread_high_priority();
 
   mlog_configure(mlog_get_default_log_path("performance_tests.log"), true);
-  mlog_set_log_level(0);
 
   po::options_description desc_options("Command line options");
   const command_line::arg_descriptor<std::string> arg_filter = { "filter", "Regular expression filter for which tests to run" };