SDL_mixer: fixed build with --disable-music-mod-xmp-shared

From d79e5f3c8ca43ad6fe3c724f82f2b1258c31d4fd Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Mon, 2 May 2022 11:37:02 +0300
Subject: [PATCH] fixed build with --disable-music-mod-xmp-shared

---
 src/codecs/music_xmp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/codecs/music_xmp.c b/src/codecs/music_xmp.c
index a3d03464..30f0da13 100644
--- a/src/codecs/music_xmp.c
+++ b/src/codecs/music_xmp.c
@@ -65,7 +65,7 @@ static xmp_loader libxmp;
 #else
 #define FUNCTION_LOADER(FUNC, SIG) \
     libxmp.FUNC = FUNC; \
-    if (lib.FUNC == NULL) { Mix_SetError("Missing xmp.framework"); return -1; }
+    if (libxmp.FUNC == NULL) { Mix_SetError("Missing xmp.framework"); return -1; }
 #endif
 
 static int XMP_Load(void)