cppcheck: fix a false-positive memLeak warning

src/cmdu.c

@@ -250,7 +250,7 @@ struct cmdu_buff *cmdu_alloc(int size)
 	n->head -= 18;
 	INIT_LIST_HEAD(&n->fraglist);
 
-	return n;
+	return (struct cmdu_buff *)p;
 }
 
 struct cmdu_buff *cmdu_alloc_frame(int size)