gui/channellist.cpp: reuse code as updateSelection()

Origin commit data
------------------
Commit: 3d5d834f3c
Author: [CST] Focus <focus.cst@gmail.com>
Date: 2012-04-04 (Wed, 04 Apr 2012)

src/gui/channellist.h

@@ -89,6 +89,7 @@ private:
 	void clearItem2DetailsLine ();
 	void paintItem2DetailsLine (int pos, int ch_index);
 	void paintItem(int pos);
+	bool updateSelection(int newpos);
 	void paint();
 	void paintHead();
 	void paintButtonBar(bool is_current);