SDL: Additional cleanup for SDL_RWprintf() (thanks @sezero!)

SDL Commits
1 
From 2a1660ab51e3d7dc87986e043bd0fdcd4951bf99 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Sat, 4 Nov 2023 20:47:08 -0700
Subject: [PATCH] Additional cleanup for SDL_RWprintf() (thanks @sezero!)

---
 include/SDL3/SDL_rwops.h |  2 +-
 src/file/SDL_rwops.c     | 14 ++++++++++----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/include/SDL3/SDL_rwops.h b/include/SDL3/SDL_rwops.h
index 73e655796365..88495d158361 100644
--- a/include/SDL3/SDL_rwops.h
+++ b/include/SDL3/SDL_rwops.h
@@ -518,7 +518,7 @@ extern DECLSPEC size_t SDLCALL SDL_RWwrite(SDL_RWops *context, const void *ptr,
  * \sa SDL_RWseek
  * \sa SDL_RWwrite
  */
-extern DECLSPEC size_t SDLCALL SDL_RWprintf(SDL_RWops *context, SDL_PRINTF_FORMAT_STRING const char *fmt, ...);
+extern DECLSPEC size_t SDLCALL SDL_RWprintf(SDL_RWops *context, SDL_PRINTF_FORMAT_STRING const char *fmt, ...)  SDL_PRINTF_VARARG_FUNC(2);
 
 /**
  * Print to an SDL_RWops data stream.
diff --git a/src/file/SDL_rwops.c b/src/file/SDL_rwops.c
index b6f943f1c68c..3bfb969b47b6 100644
--- a/src/file/SDL_rwops.c
+++ b/src/file/SDL_rwops.c
@@ -812,14 +812,17 @@ size_t SDL_RWprintf(SDL_RWops *context, SDL_PRINTF_FORMAT_STRING const char *fmt
 {
     va_list ap;
     int size;
-    char *string = NULL;
+    char *string;
     size_t bytes;
 
     va_start(ap, fmt);
     size = SDL_vasprintf(&string, fmt, ap);
     va_end(ap);
+    if (size < 0) {
+        return 0;
+    }
 
-    bytes = SDL_RWwrite(context, string, size);
+    bytes = SDL_RWwrite(context, string, (size_t)size);
     SDL_free(string);
     return bytes;
 }
@@ -827,12 +830,15 @@ size_t SDL_RWprintf(SDL_RWops *context, SDL_PRINTF_FORMAT_STRING const char *fmt
 size_t SDL_RWvprintf(SDL_RWops *context, const char *fmt, va_list ap)
 {
     int size;
-    char *string = NULL;
+    char *string;
     size_t bytes;
 
     size = SDL_vasprintf(&string, fmt, ap);
+    if (size < 0) {
+        return 0;
+    }
 
-    bytes = SDL_RWwrite(context, string, size);
+    bytes = SDL_RWwrite(context, string, (size_t)size);
     SDL_free(string);
     return bytes;
 }