sdl2-compat: silence a 'may be used uninitialized' warning

SDL Commits
1 
From 98ef5b1bd9eb708716ccd28a00b06827cfef5f14 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Fri, 3 Feb 2023 20:55:04 +0300
Subject: [PATCH] silence a 'may be used uninitialized' warning

sdl2_compat.c:3489: warning: 'mode3.displayID' may be used uninitialized in this function
sdl2_compat.c:3603: note: 'mode3.displayID' was declared here
---
 src/sdl2_compat.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/sdl2_compat.c b/src/sdl2_compat.c
index c06e79f..f24d100 100644
--- a/src/sdl2_compat.c
+++ b/src/sdl2_compat.c
@@ -3609,15 +3609,19 @@ SDL_GetClosestDisplayMode(int displayIndex, const SDL2_DisplayMode *mode, SDL2_D
         return NULL;
     }
 
+    /* silence compiler */
+    SDL3_zero(mode3);
+    SDL3_zero(closest3);
+
     DisplayMode_2to3(closest, &closest3);
     DisplayMode_2to3(mode, &mode3);
     ret3 = SDL_GetClosestDisplayModeForDisplay(Display_IndexToID(displayIndex), &mode3, &closest3);
     if (ret3 == NULL) {
         return NULL;
-    } else {
-        DisplayMode_3to2(ret3, closest);
-        return closest;
     }
+
+    DisplayMode_3to2(ret3, closest);
+    return closest;
 }
 
 DECLSPEC int SDLCALL