SDL: further mouse relative motion fix for os/2 (thanks Andrey Vasilkin)

SDL Commits
1 
From f5b3247aae0c4778dd7932c91c295c9ed9e17d17 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Thu, 8 Jun 2023 03:40:32 +0300
Subject: [PATCH] further mouse relative motion fix for os/2 (thanks Andrey
 Vasilkin)

---
 src/video/os2/SDL_os2mouse.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/video/os2/SDL_os2mouse.c b/src/video/os2/SDL_os2mouse.c
index bcbb4b40366f..3ffdef917cdd 100644
--- a/src/video/os2/SDL_os2mouse.c
+++ b/src/video/os2/SDL_os2mouse.c
@@ -122,11 +122,9 @@ static void OS2_WarpMouse(SDL_Window * window, int x, int y)
     POINTL      pointl;
 
     pointl.x = x;
-    pointl.y = window->h - y;
+    pointl.y = window->h - y - 1;
     WinMapWindowPoints(pWinData->hwnd, HWND_DESKTOP, &pointl, 1);
-/*  pWinData->lSkipWMMouseMove++; ???*/
     WinSetPointerPos(HWND_DESKTOP, pointl.x, pointl.y);
-
     SDL_SendMouseMotion(window, SDL_GetMouse()->mouseID, 0, x, y);
 }