sdl2-compat: Fix invalid read: displayID wasn't set

SDL Commits
1 
From 59c3f20a84f764614d0eeb462bd5de88050b9b75 Mon Sep 17 00:00:00 2001
From: Sylvain <[EMAIL REDACTED]>
Date: Wed, 20 Dec 2023 09:35:14 +0100
Subject: [PATCH] Fix invalid read: displayID wasn't set

---
 src/sdl2_compat.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/sdl2_compat.c b/src/sdl2_compat.c
index 703e3d0..74f34d1 100644
--- a/src/sdl2_compat.c
+++ b/src/sdl2_compat.c
@@ -5575,6 +5575,7 @@ SDL_SetWindowDisplayMode(SDL_Window *window, const SDL2_DisplayMode *mode)
 {
     SDL_DisplayMode dp;
     DisplayMode_2to3(mode, &dp);
+    dp.displayID = SDL3_GetDisplayForWindow(window);
     if (SDL3_SetWindowFullscreenMode(window, mode ? &dp : NULL) == 0) {
         return 0;
     } else {