Fix analyzer errors in the http_parser web socket test.

pkg/http_parser/test/web_socket_test.dart

Index: pkg/http_parser/test/web_socket_test.dart
diff --git a/pkg/http_parser/test/web_socket_test.dart b/pkg/http_parser/test/web_socket_test.dart
index 5eadbff65c4c95a9575ba4a7ed884302da509b8c..45b84d9ec759946a1e7ae375d56943255f0bbeb6 100644
--- a/pkg/http_parser/test/web_socket_test.dart
+++ b/pkg/http_parser/test/web_socket_test.dart
@@ -43,7 +43,7 @@ void main() {
             webSocket.close();
             server.close();
           } else {
-            expect(false, reason: "Only expected two messages.");
+            fail("Only expected two messages.");
           }
           n++;
         }).asFuture();
@@ -85,7 +85,7 @@ void main() {
             webSocket.close();
             server.close();
           } else {
-            expect(false, reason: "Only expected two messages.");
+            fail("Only expected two messages.");
           }
           n++;
         }).asFuture();