Properly close the Linux directory watcher when listing a subdirectory fails.

pkg/watcher/lib/src/directory_watcher/linux.dart

Index: pkg/watcher/lib/src/directory_watcher/linux.dart
diff --git a/pkg/watcher/lib/src/directory_watcher/linux.dart b/pkg/watcher/lib/src/directory_watcher/linux.dart
index 519607839a780a87d73a70ec8a2e4fe24a3f1cdc..d62c6ef10d42e729c81de68bcd6fc5874d9ebb24 100644
--- a/pkg/watcher/lib/src/directory_watcher/linux.dart
+++ b/pkg/watcher/lib/src/directory_watcher/linux.dart
@@ -166,7 +166,7 @@ class _LinuxDirectoryWatcher implements ManuallyClosedDirectoryWatcher {
         if (error is FileSystemException) return;
 
         _eventsController.addError(error, stackTrace);
-        _eventsController.close();
+        close();
       }, cancelOnError: true);
     });
   }