SDL: emscripten: Replace a stray reference to SDL2 with SDL3

SDL Commits
1 
From 45ebdfb1dcf78f49496a9249cc1cb35037f75c9f Mon Sep 17 00:00:00 2001
From: Simon McVittie <[EMAIL REDACTED]>
Date: Tue, 13 Dec 2022 12:18:54 +0000
Subject: [PATCH] emscripten: Replace a stray reference to SDL2 with SDL3

Entirely untested, but I'm fairly sure this is what was intended.

Signed-off-by: Simon McVittie <smcv@collabora.com>
---
 src/video/emscripten/SDL_emscriptenframebuffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/video/emscripten/SDL_emscriptenframebuffer.c b/src/video/emscripten/SDL_emscriptenframebuffer.c
index 520bd7600abd..3500ad44cf6b 100644
--- a/src/video/emscripten/SDL_emscriptenframebuffer.c
+++ b/src/video/emscripten/SDL_emscriptenframebuffer.c
@@ -97,7 +97,7 @@ int Emscripten_UpdateWindowFramebuffer(_THIS, SDL_Window *window, const SDL_Rect
             SDL3.data8 = new Uint8Array(data.buffer);
             SDL3.data32Data = data;
         }
-        var data32 = SDL2.data32;
+        var data32 = SDL3.data32;
         num = data32.length;
         // logically we need to do
         //      while (dst < num) {