py: Simplify bytecode prelude when encoding closed over variables.
diff --git a/py/showbc.c b/py/showbc.c
index 3a46832..c9eeaff 100644
--- a/py/showbc.c
+++ b/py/showbc.c
@@ -95,10 +95,8 @@
 
     // bytecode prelude: initialise closed over variables
     {
-        uint n_local = *ip++;
-        printf("(NUM_LOCAL %u)\n", n_local);
-        for (; n_local > 0; n_local--) {
-            uint local_num = *ip++;
+        uint local_num;
+        while ((local_num = *ip++) != 255) {
             printf("(INIT_CELL %u)\n", local_num);
         }
         len -= ip - mp_showbc_code_start;