switch_xml_unbind_search_function_ptr function node delete error

[langyalian]

Describe the bug
The last node should not be moved when deleting a node

SWITCH_DECLARE(switch_status_t) switch_xml_unbind_search_function_ptr(switch_xml_search_function_t function)
{
	switch_xml_binding_t *ptr, *last = NULL;
	switch_status_t status = SWITCH_STATUS_FALSE;

	switch_thread_rwlock_wrlock(B_RWLOCK);
	for (ptr = BINDINGS; ptr; ptr = ptr->next) {
		if (ptr->function == function) {
			status = SWITCH_STATUS_SUCCESS;

			if (last) {
				last->next = ptr->next;
                                /* Add */
				continue;
			} else {
				BINDINGS = ptr->next;
				last = NULL;
				continue;
			}
		}
		last = ptr;
	}
	switch_thread_rwlock_unlock(B_RWLOCK);

	return status;
}