sdl12-compat: change two SDL_SetError() calls to SDL20_SetError()

SDL Commits
1 
From 413f6db4ae4b4a4e28abc7a65674d840bfe7895d Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Mon, 1 Mar 2021 14:00:04 +0300
Subject: [PATCH] change two SDL_SetError() calls to SDL20_SetError()

---
 src/SDL12_compat.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/SDL12_compat.c b/src/SDL12_compat.c
index 91f5040..7b58a66 100644
--- a/src/SDL12_compat.c
+++ b/src/SDL12_compat.c
@@ -3298,8 +3298,7 @@ SDL_UpperBlit(SDL12_Surface *src12, SDL12_Rect *srcrect12, SDL12_Surface *dst12,
     int retval;
 
     if ((src12 == NULL) || (dst12 == NULL)) {
-        SDL_SetError("SDL_UpperBlit: passed a NULL surface");
-        return -1;
+        return SDL20_SetError("SDL_UpperBlit: passed a NULL surface");
     } else if (SaveDestAlpha(src12, dst12, &dstalpha) < 0) {
         return -1;
     }
@@ -4285,7 +4284,7 @@ DECLSPEC SDL12_RWops * SDLCALL
 SDL_RWFromFile(const char *file, const char *mode)
 {
     if (!file || !*file || !mode || !*mode) {
-        SDL_SetError("SDL_RWFromFile(): No file or no mode specified");
+        SDL20_SetError("SDL_RWFromFile(): No file or no mode specified");
         return NULL;
     }
     return RWops20to12(SDL20_RWFromFile(file, mode));