SDL_image: Reset SDL2_image_FOUND instead of SDL3_image_FOUND

SDL Commits
1 
From 251cdd89247b25f57edc1a87dfcf17e9a8a4b407 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Tue, 3 Dec 2024 08:37:14 -0800
Subject: [PATCH] Reset SDL2_image_FOUND instead of SDL3_image_FOUND

Fixes https://github.com/libsdl-org/SDL_image/issues/483
---
 SDL2_imageConfig.cmake.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/SDL2_imageConfig.cmake.in b/SDL2_imageConfig.cmake.in
index c59e8449..7c7efab5 100644
--- a/SDL2_imageConfig.cmake.in
+++ b/SDL2_imageConfig.cmake.in
@@ -50,7 +50,7 @@ if(SDL2IMAGE_AVIF AND NOT SDL2IMAGE_VENDORED AND NOT TARGET avif)
         find_package(libavif @LIBAVIF_MINIMUM_VERSION@ QUIET)
     endif()
     if(NOT libavif_FOUND)
-        set(SDL3_image_FOUND FALSE)
+        set(SDL2_image_FOUND FALSE)
         return()
     endif()
 endif()