Cleanup benchmark

Avoid unnecessary consecutive ucinewgame commands in benchmark setup.
Remove measuring time and nodes in speedtest warmup.

closes https://github.com/official-stockfish/Stockfish/pull/6427

No functional change

src/benchmark.cpp

@@ -483,7 +483,6 @@ BenchmarkSetup setup_benchmark(std::istream& is) {
     float totalTime = 0;
     for (const auto& game : BenchmarkPositions)
     {
-        setup.commands.emplace_back("ucinewgame");
         int ply = 1;
         for (int i = 0; i < static_cast<int>(game.size()); ++i)
         {

src/uci.cpp

@@ -339,16 +339,9 @@ void UCIEngine::benchmark(std::istream& args) {
 
             Search::LimitsType limits = parse_limits(is);
 
-            TimePoint elapsed = now();
-
             // Run with silenced network verification
             engine.go(limits);
             engine.wait_for_search_finished();
-
-            totalTime += now() - elapsed;
-
-            nodes += nodesSearched;
-            nodesSearched = 0;
         }
         else if (token == "position")
             position(is);
@@ -396,6 +389,7 @@ void UCIEngine::benchmark(std::istream& args) {
 
             Search::LimitsType limits = parse_limits(is);
 
+            nodesSearched     = 0;
             TimePoint elapsed = now();
 
             // Run with silenced network verification
@@ -407,7 +401,6 @@ void UCIEngine::benchmark(std::istream& args) {
             updateHashfullReadings();
 
             nodes += nodesSearched;
-            nodesSearched = 0;
         }
         else if (token == "position")
             position(is);