SDL: Fixed warning building with Visual Studio

SDL Commits
1 
From 996b3dc37afce0153b600b8fff3bca16d0d94a0a Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Sun, 15 May 2022 09:33:28 -0700
Subject: [PATCH] Fixed warning building with Visual Studio

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

diff --git a/src/SDL_assert.c b/src/SDL_assert.c
index 04299a9b168..02cd6b3fd1d 100644
--- a/src/SDL_assert.c
+++ b/src/SDL_assert.c
@@ -182,7 +182,7 @@ SDL_PromptAssertion(const SDL_assert_data *data, void *userdata)
     len = SDL_RenderAssertMessage(message, buf_len, data);
 
     /* .. and if it didn't, try to allocate as much room as we actually need. */
-    if (len >= buf_len) {
+    if (len >= (int)buf_len) {
         if (SDL_size_add_overflow(len, 1, &buf_len) == 0) {
             message = (char *)SDL_malloc(buf_len);
             if (message) {