lib: Fix free function

lib: Fix free function

The list delete function on creation was set to srv6_locator_chunk_free
Which takes a double pointer and dereferences it to free the data.
When list_delete is called it calls the delete function like this:
                if (*list->del)
                        (*list->del)(node->data);

The data is not passed in by reference and as such we do not have
a double pointer.  Fortunately this list_delete is only really
called on shutdown when the locator was deleted and we do not
have a fun situation where we were suddenly freeing 'something'.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>