test: make ValidateCount throw an error instead of a log

We can either fix it here or at every callsite. Every callsite is
currently using this method incorrectly.

Signed-off-by: Mike Danese <mikedanese@google.com>

pkg/controller/replication/replication_controller_test.go

@@ -295,7 +295,7 @@ func TestSyncReplicationControllerDormancy(t *testing.T) {
 	// Setup a test server so we can lie about the current state of pods
 	fakeHandler := utiltesting.FakeHandler{
 		StatusCode:   200,
-		ResponseBody: "",
+		ResponseBody: "{}",
 	}
 	testServer := httptest.NewServer(&fakeHandler)
 	// TODO: Uncomment when fix #19254