SDL: testaudio: Apparently compilers don't like this possibly being NULL now...?

https://github.com/libsdl-org/SDL/commit/1b1f02c5aaec5631cf98262ee70f0217c010ae7c

From 1b1f02c5aaec5631cf98262ee70f0217c010ae7c Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Wed, 2 Aug 2023 15:07:40 -0400
Subject: [PATCH] testaudio: Apparently compilers don't like this possibly
 being NULL now...?

---
 test/testaudio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/testaudio.c b/test/testaudio.c
index d8ca140567f7..ff0fb27a83fc 100644
--- a/test/testaudio.c
+++ b/test/testaudio.c
@@ -591,7 +591,7 @@ static Thing *CreateStreamThing(const SDL_AudioSpec *spec, const Uint8 *buf, con
 {
     static const ThingType can_be_dropped_onto[] = { THING_TRASHCAN, THING_LOGDEV, THING_LOGDEV_CAPTURE, THING_NULL };
     Thing *thing = CreateThing(THING_STREAM, x, y, 0, -1, -1, soundboard_texture, fname ? xstrdup(fname) : NULL);
-    SDL_Log("Adding audio stream for %s", fname);
+    SDL_Log("Adding audio stream for %s", fname ? fname : "(null)");
     thing->data.stream.stream = SDL_CreateAudioStream(spec, spec);
     if (buf && buflen) {
         SDL_PutAudioStreamData(thing->data.stream.stream, buf, (int) buflen);