Added missing WIN_ReleaseWndPtr.

dlls/ddraw/ddraw/xvidmode.c

diff --git a/dlls/ddraw/ddraw/xvidmode.c b/dlls/ddraw/ddraw/xvidmode.c
index b16d452..95408aa 100644
--- a/dlls/ddraw/ddraw/xvidmode.c
+++ b/dlls/ddraw/ddraw/xvidmode.c
@@ -341,6 +341,7 @@
 	XF86VidModeModeInfo* new_mode;
         WND *tmpWnd = WIN_FindWndPtr(This->window);
         Window x11Wnd = X11DRV_WND_GetXWindow(tmpWnd);
+        WIN_ReleaseWndPtr(tmpWnd);
 
 	new_mode = choose_mode(dwWidth, dwHeight, dwRefreshRate, dwFlags);