sdl2-compat: silence an MSVC warning.

SDL Commits
1 
From b7f79f9c8b2ee7fe9936a8de1ec4562f4b341fe9 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Thu, 6 Apr 2023 14:28:11 +0300
Subject: [PATCH] silence an MSVC warning.

---
 src/sdl2_compat.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/sdl2_compat.c b/src/sdl2_compat.c
index 0e22227..622d5b8 100644
--- a/src/sdl2_compat.c
+++ b/src/sdl2_compat.c
@@ -4038,9 +4038,10 @@ SDL_GetClosestDisplayModeForDisplay(SDL_DisplayID displayID,
             closest->screen_h = 480;
         }
         SDL_FinalizeDisplayMode(closest);
-        SDL_free(list);
+        SDL_free((void *)list);
         return closest;
     }
+
     SDL_free((void *)list);
     return NULL;
 }