Return old behaviour and execute void benchmarks

Author: YegorStepanov

src/BenchmarkDotNet/Validators/ReturnValueValidator.cs

@@ -27,13 +27,12 @@ protected override void ExecuteBenchmarks(IEnumerable<BenchmarkExecutor> executo
 
                 foreach (var executor in parameterGroup.DistinctBy(e => e.BenchmarkCase.Descriptor.WorkloadMethod))
                 {
-                    if (executor.BenchmarkCase.Descriptor.WorkloadMethod.ReturnType == typeof(void))
-                        return;
-
                     try
                     {
                         var result = executor.Invoke();
-                        results.Add((executor.BenchmarkCase, result));
+
+                        if (executor.BenchmarkCase.Descriptor.WorkloadMethod.ReturnType != typeof(void))
+                            results.Add((executor.BenchmarkCase, result));
                     }
                     catch (Exception ex)
                     {
@@ -159,4 +158,4 @@ static Array ToStructuralEquatable(object obj)
             public int GetHashCode(object obj) => StructuralComparisons.StructuralEqualityComparer.GetHashCode(obj);
         }
     }
-}
+}