fixed error on compiling without SVBCam

videodev.h

@@ -119,7 +119,9 @@ private:
 	virtual int GetDevCtrl(unsigned int id, int *value) { return VDEV_STATUS_OK; };
 
 	friend class VideoDev_V4L2;
+#ifdef USE_SVBONY
 	friend class VideoDev_SVBCam;
+#endif
 public:
 	VideoDev();
 	virtual ~VideoDev();