silence unused parameter warning

diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index 01e91ea2ee4dca375f3062faf54e657a9d5b035b..625891ca878829eb1d002a34add939b92ff6ac1f 100644 (file)
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -4545,6 +4545,11 @@ check_stale_rdataset(dns_rbtnode_t *node, rdatasetheader_t *header,
                     isc_rwlocktype_t *locktype, nodelock_t *lock,
                     rbtdb_search_t *search, rdatasetheader_t **header_prev)
 {
+
+#if !defined(ISC_RWLOCK_USEATOMIC) || !defined(DNS_RBT_USEISCREFCOUNT)
+       UNUSED(lock);
+#endif
+
        if (header->rdh_ttl < search->now) {
                /*
                 * This rdataset is stale.  If no one else is using the