SDL_image: Use false where appropriate

SDL Commits
1 
From 327951654a29f02633641a62b61d648f12175b6d Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Wed, 18 Sep 2024 12:04:52 -0700
Subject: [PATCH] Use false where appropriate

---
 src/IMG_avif.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/IMG_avif.c b/src/IMG_avif.c
index 76484193..96e1ca5b 100644
--- a/src/IMG_avif.c
+++ b/src/IMG_avif.c
@@ -208,7 +208,7 @@ bool IMG_isAVIF(SDL_IOStream *src)
     }
 
     start = SDL_TellIO(src);
-    is_AVIF = 0;
+    is_AVIF = false;
     if (ReadAVIFHeader(src, &data, &size)) {
         /* This might be AVIF, do more thorough checks */
         if ((IMG_Init(IMG_INIT_AVIF) & IMG_INIT_AVIF) != 0) {