SDL: Sync SDL3 wiki -> header (6f45f)

From 6f45f97af0ebaa963f2efb971540b08b199e264c Mon Sep 17 00:00:00 2001
From: SDL Wiki Bot <[EMAIL REDACTED]>
Date: Tue, 10 Feb 2026 15:51:32 +0000
Subject: [PATCH] Sync SDL3 wiki -> header

[ci skip]
---
 include/SDL3/SDL_log.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/SDL3/SDL_log.h b/include/SDL3/SDL_log.h
index 2ae0963c2b415..f193abfb3b30b 100644
--- a/include/SDL3/SDL_log.h
+++ b/include/SDL3/SDL_log.h
@@ -487,7 +487,8 @@ typedef void (SDLCALL *SDL_LogOutputFunction)(void *userdata, int category, SDL_
 /**
  * Get the default log output function.
  *
- * \returns the default log output callback.
+ * \returns the default log output callback. It should be called with NULL for
+ *          the userdata argument.
  *
  * \threadsafety It is safe to call this function from any thread.
  *