Fix typo in previous commit.

tests/standalone/io/raw_server_socket_cancel_test.dart

Index: tests/standalone/io/raw_server_socket_cancel_test.dart
diff --git a/tests/standalone/io/raw_server_socket_cancel_test.dart b/tests/standalone/io/raw_server_socket_cancel_test.dart
index a927c7cd02dd0dc939ac2cd034f0ab5483babc6e..32795279597fe5794b6d7a39241caff9143d49d7 100644
--- a/tests/standalone/io/raw_server_socket_cancel_test.dart
+++ b/tests/standalone/io/raw_server_socket_cancel_test.dart
@@ -28,7 +28,7 @@ void testCancelResubscribeServerSocket(int socketCount, int backlog) {
         port.close();
         // Be sure to close as subscription.cancel may not be called, if
         // backlog prevents acceptCount to grow to socketCount / 2.
-        socket.close();
+        server.close();
       }
     }