SDL: Fix compilation / same as sdl2-compat

SDL Commits
1 
From 56f111dffc2828d67fd8e0402b0fe1193c48ce26 Mon Sep 17 00:00:00 2001
From: Sylvain <[EMAIL REDACTED]>
Date: Wed, 20 Dec 2023 09:40:09 +0100
Subject: [PATCH] Fix compilation / same as sdl2-compat
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testautomation_platform.c:351:28: error: ‘%s’ directive argument is null [-Werror=format-overflow=]
  351 |     result = SDL_SetError("%s", testError);
      |                            ^~
/home/slvn/release/Release_SDL/sdl2-compat/test/testautomation_platform.c:364:64: error: ‘%s’ directive argument is null [-Werror=format-overflow=]
  364 |                             "SDL_GetError(): expected message '%s', was message: '%s'",
---
 test/testautomation_platform.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/testautomation_platform.c b/test/testautomation_platform.c
index dcb379b8763b..0e1ddd1c53cf 100644
--- a/test/testautomation_platform.c
+++ b/test/testautomation_platform.c
@@ -369,7 +369,7 @@ static int platform_testSetErrorEmptyInput(void *arg)
 static int platform_testSetErrorInvalidInput(void *arg)
 {
     int result;
-    const char *invalidError = NULL;
+    const char *invalidError = "";
     const char *probeError = "Testing";
     const char *lastError;
     size_t len;