Really update return type of dart2js patch of dart:developer.log.

sdk/lib/_internal/js_runtime/lib/developer_patch.dart

Index: sdk/lib/_internal/js_runtime/lib/developer_patch.dart
diff --git a/sdk/lib/_internal/js_runtime/lib/developer_patch.dart b/sdk/lib/_internal/js_runtime/lib/developer_patch.dart
index 4f06174d37d9bd48c068ef01b304081045dec19e..2b5ba7ea055e050566d4a8f8b27357cf909efd57 100644
--- a/sdk/lib/_internal/js_runtime/lib/developer_patch.dart
+++ b/sdk/lib/_internal/js_runtime/lib/developer_patch.dart
@@ -22,13 +22,13 @@ Object inspect(Object object) {
 }
 
 @patch
-log(String message,
-    {DateTime time,
-     int sequenceNumber,
-     int level: 0,
-     String name: '',
-     Zone zone,
-     Object error,
-     StackTrace stackTrace}) {
+void log(String message,
+         {DateTime time,
+          int sequenceNumber,
+          int level: 0,
+          String name: '',
+          Zone zone,
+          Object error,
+          StackTrace stackTrace}) {
   // TODO.
 }