Fix -d all hot reload (#12178)

packages/flutter_tools/lib/src/run_hot.dart

@@ -502,6 +502,7 @@ class HotRunner extends ResidentRunner {
           // `validateReloadReport` is called again.
           device.updateReloadStatus(validateReloadReport(firstReport,
             printErrors: false));
+          if (!retrieveFirstReloadReport.isCompleted)
             retrieveFirstReloadReport.complete(firstReport);
         }, onError: (dynamic error, StackTrace stack) {
           retrieveFirstReloadReport.completeError(error, stack);