Fix warnings in MediaBrowser.Controller/Library

MediaBrowser.Controller/Library/IMetadataSaver.cs

@@ -29,7 +29,6 @@ namespace MediaBrowser.Controller.Library
         /// </summary>
         /// <param name="item">The item.</param>
         /// <param name="cancellationToken">The cancellation token.</param>
-        /// <returns>Task.</returns>
         void Save(BaseItem item, CancellationToken cancellationToken);
     }
 }