fixed the test (it violated the docs...)

git-svn-id: https://robotics.mvla.net/svn/frc971/2013/trunk/src@4186 f308d9b7-e957-4cde-b6ac-9a88185e7312
diff --git a/aos/common/once_test.cc b/aos/common/once_test.cc
index ed21b37..7c6e5de 100644
--- a/aos/common/once_test.cc
+++ b/aos/common/once_test.cc
@@ -114,6 +114,7 @@
 // Tests calling Reset() to run the function a second time.
 TEST_F(OnceTest, Recalculate) {
   Once<int> once(Function);
+  once.Reset();
 
   EXPECT_EQ(value_, *once.Get());
   EXPECT_EQ(1, times_run_);