revert change in task_scheduler.cc

src/meta_schedule/task_scheduler/task_scheduler.cc

@@ -128,18 +128,7 @@ void TaskSchedulerNode::Tune() {
     ICHECK(!task->is_terminated);
     ICHECK(!task->runner_futures.defined());
     SearchStrategy strategy = task->search_strategy.value();
-    Optional<Array<MeasureCandidate>> candidates = strategy->GenerateMeasureCandidates();
-    if (candidates.defined()) {
-      // Filter out invalid candidates.
-      // An invalid candidate can arise due to a schdule application failure (e.g. tensorize).
-      Array<MeasureCandidate> valid_candidates;
-      for (MeasureCandidate candidate : candidates.value()) {
-        if (candidate.defined()) {
-          valid_candidates.push_back(candidate);
-        }
-      }
-
-      task->measure_candidates = std::move(valid_candidates);
+    if ((task->measure_candidates = strategy->GenerateMeasureCandidates()).defined()) {
       num_trials_already += task->measure_candidates.value().size();
       SendToBuilder(this->builder, task);
       SendToRunner(this->runner, task);