port: read gbi command id correctly in gfxReplaceGbiCommands

src/game/gfxreplace.c

@@ -308,7 +308,11 @@ void gfxReplaceGbiCommands(Gfx *startgdl, Gfx *endgdl, s32 type)
 
 	Gfx *gdl = startgdl;
 
+#ifdef PLATFORM_N64
 	while ((endgdl && gdl < endgdl) || (!endgdl && *(s8 *)gdl != G_ENDDL)) {
+#else
+	while ((endgdl && gdl < endgdl) || (!endgdl && (s8)gdl->bytes[GFX_W0_BYTE(0)] != G_ENDDL)) {
+#endif
 		Gfx *src = groups[type];
 
 		while (src->words.w0 != 0) {