Fixes for C23 Support (#2138)

* fixes for c23 support
* include global.h in m4a.c & remove <string.h> include

include/librfu.h

@@ -316,7 +316,11 @@ struct STWIStatus
     u8 recoveryCount;
     u8 unk_16;
     u8 unk_17;
+#if !MODERN
     void (*callbackM)();
+#else
+    void (*callbackM)(...);
+#endif
     void (*callbackS)(u16);
     void (*callbackID)(void);
     union RfuPacket *txPacket;