fix

Author: Ekdohibs

middle_end/flambda2/from_lambda/closure_conversion.ml

@@ -1763,9 +1763,9 @@ let close_one_function acc ~code_id ~external_env ~by_function_slot
         Bound_parameters.create main_code_params,
         main_code_param_modes,
         false,
-        (* num_trailing_local_closures = all params: function should never be
-           partially applied anyway *)
-        List.length main_code_params - 1,
+        (* num_trailing_local_closures = all params, but function should never
+           be partially applied anyway *)
+        List.length main_code_params,
         result_arity_main_code,
         unboxed_return_continuation,
         my_unboxed_closure )