SDL: Use SDL_strdup instead of strdup

SDL Commits
1 
From 62ed6f453f6226784c1a47baf6bc544aed15fa7f Mon Sep 17 00:00:00 2001
From: Mathieu Eyraud <[EMAIL REDACTED]>
Date: Thu, 15 Jun 2023 09:59:07 +0200
Subject: [PATCH] Use SDL_strdup instead of strdup

---
 src/video/x11/SDL_x11clipboard.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/video/x11/SDL_x11clipboard.c b/src/video/x11/SDL_x11clipboard.c
index 7cd58a0ad3c6..41098409f8f9 100644
--- a/src/video/x11/SDL_x11clipboard.c
+++ b/src/video/x11/SDL_x11clipboard.c
@@ -234,7 +234,7 @@ static void *GetSelectionData(SDL_VideoDevice *_this, Atom selection_type, size_
     }
 
     if (nullterminate && data == NULL) {
-        data = strdup("");
+        data = SDL_strdup("");
     }
 
     return data;