Clear window for removing remaining color

When we switch disk, some parts of status are changed.
With the status change, color are also changed but sometime remaining
old color.
For fixing it, this commit is adding wclear() for each window.

main.cpp

@@ -448,8 +448,11 @@ int main()
 	update = [&]()
 	{
 		getmaxyx(stdscr, height, width);
+		wclear(windowVersion);
 		drawVersion(windowVersion);
+		wclear(windowDeviceBar);
 		drawDeviceBar(windowDeviceBar, smartList, select);
+		wclear(windowDeviceStatus);
 		drawStatus(windowDeviceStatus, smartList[select]);
 		doupdate();
 	};