refs/reftable: reload correct stack when creating reflog iter

When creating a new reflog iterator, we first have to reload the stack
that the iterator is being created. This is done so that any concurrent
writes to the stack are reflected. But `reflog_iterator_for_stack()`
always reloads the main stack, which is wrong.

Fix this and reload the correct stack.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

refs/reftable-backend.c

@@ -1682,7 +1682,7 @@ static struct reftable_reflog_iterator *reflog_iterator_for_stack(struct reftabl
 	if (ret)
 		goto done;
 
-	ret = reftable_stack_reload(refs->main_stack);
+	ret = reftable_stack_reload(stack);
 	if (ret < 0)
 		goto done;