SDL: README-migration: patched SDL_RWFromFP replacement code to compile.

SDL Commits
1 
From 8ee03d68bd8d34aef2667c23194b70efee940c21 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Sat, 27 Jun 2026 16:56:29 -0400
Subject: [PATCH] README-migration: patched SDL_RWFromFP replacement code to
 compile.

Reference Issue #15893.
---
 docs/README-migration.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/docs/README-migration.md b/docs/README-migration.md
index 3fd243c8f2a99..2dc1002f8ab58 100644
--- a/docs/README-migration.md
+++ b/docs/README-migration.md
@@ -1531,7 +1531,7 @@ typedef struct IOStreamStdioFPData
     bool autoclose;
 } IOStreamStdioFPData;
 
-static Sint64 SDLCALL stdio_seek(void *userdata, Sint64 offset, int whence)
+static Sint64 SDLCALL stdio_seek(void *userdata, Sint64 offset, SDL_IOWhence whence)
 {
     FILE *fp = ((IOStreamStdioFPData *) userdata)->fp;
     int stdiowhence;
@@ -1551,7 +1551,7 @@ static Sint64 SDLCALL stdio_seek(void *userdata, Sint64 offset, int whence)
         return -1;
     }
 
-    if (fseek(fp, (fseek_off_t)offset, stdiowhence) == 0) {
+    if (fseek(fp, (long)offset, stdiowhence) == 0) {
         const Sint64 pos = ftell(fp);
         if (pos < 0) {
             SDL_SetError("Couldn't get stream offset");
@@ -1585,7 +1585,7 @@ static size_t SDLCALL stdio_write(void *userdata, const void *ptr, size_t size,
 
 static bool SDLCALL stdio_close(void *userdata)
 {
-    IOStreamStdioData *rwopsdata = (IOStreamStdioData *) userdata;
+    IOStreamStdioFPData *rwopsdata = (IOStreamStdioFPData *) userdata;
     bool status = true;
     if (rwopsdata->autoclose) {
         if (fclose(rwopsdata->fp) != 0) {