improve socket disposal

MediaBrowser.Dlna/Ssdp/DeviceDiscovery.cs

@@ -109,8 +109,8 @@ namespace MediaBrowser.Dlna.Ssdp
 
 					var endPoint = new IPEndPoint(localIp, 1900);
 
-                    var socket = GetMulticastSocket(localIp, endPoint);
+                    using (var socket = GetMulticastSocket(localIp, endPoint))
-
+                    {
                         var receiveBuffer = new byte[64000];
 
                         CreateNotifier(localIp);
@@ -135,6 +135,7 @@ namespace MediaBrowser.Dlna.Ssdp
                                 TryCreateDevice(args);
                             }
                         }
+                    }
 
                     _logger.Info("SSDP listener - Task completed");
                 }