Fix an analyzer warning in scheduled_test.

pkg/scheduled_test/lib/scheduled_test.dart

Index: pkg/scheduled_test/lib/scheduled_test.dart
diff --git a/pkg/scheduled_test/lib/scheduled_test.dart b/pkg/scheduled_test/lib/scheduled_test.dart
index bba468707e2b4d8a359a8fbf63fc17383d8b72a8..9d7897a62dec03fa103ff9779108c4971b206b46 100644
--- a/pkg/scheduled_test/lib/scheduled_test.dart
+++ b/pkg/scheduled_test/lib/scheduled_test.dart
@@ -222,7 +222,7 @@ Function _setUpFn;
 ///
 /// If [body] returns a [Future], that future will automatically be wrapped with
 /// [wrapFuture].
-void test(String description, Future body()) =>
+void test(String description, body()) =>
   _test(description, body, unittest.test);
 
 /// Creates a new test case with the given description and body that will be the
@@ -232,10 +232,10 @@ void test(String description, Future body()) =>
 ///
 /// If [body] returns a [Future], that future will automatically be wrapped with
 /// [wrapFuture].
-void solo_test(String description, Future body()) =>
+void solo_test(String description, body()) =>
   _test(description, body, unittest.solo_test);
 
-void _test(String description, Future body(), Function testFn) {
+void _test(String description, body(), Function testFn) {
   maybeWrapFuture(future, description) {
     if (future != null) wrapFuture(future, description);
   }
@@ -309,7 +309,7 @@ Future schedule(fn(), [String description]) =>
 /// be scheduled for [currentSchedule.onComplete] or
 /// [currentSchedule.onException]. These tasks will be run after each test's
 /// schedule is completed.
-void setUp(void setUpFn()) {
+void setUp(setUpFn()) {
   _setUpScheduledTest(setUpFn);
 }