Replace UNUSED with _unused_

src/contrib/dnstap/reader.c

src/contrib/macros.h

src/knot/catalog/catalog_update.c

src/knot/ctl/commands.c

src/knot/dnssec/nsec3-chain.c

src/knot/dnssec/zone-sign.c

src/knot/events/handlers/freeze_thaw.c

src/knot/server/tcp-handler.c

src/knot/server/udp-handler.c

src/knot/updates/changesets.c

src/knot/zone/adjust.c

src/knot/zone/contents.c

src/knot/zone/semantic-check.c

src/knot/zone/zone-tree.c

src/knot/zone/zonedb-load.c

src/libknot/db/db_trie.c

src/libknot/libknot.h

src/utils/kjournalprint/main.c

src/utils/knsupdate/knsupdate_exec.c

tests/contrib/test_qp-cow.c