CID 430836: Dead code in lib/dns/cache.c

Coverity Scan claims dead code in lib/dns/cache.c after fa275a59:

*** CID 430836:  Control flow issues  (DEADCODE)

/lib/dns/cache.c: 406 in dns_cache_flush()
400     	UNLOCK(&cache->lock);
401     
402     	if (dbiterator != NULL) {
403     		dns_dbiterator_destroy(&dbiterator);
404     	}
405     	if (olddbiterator != NULL) {
>>>     CID 430836:  Control flow issues  (DEADCODE)
>>>     Execution cannot reach this statement: "dns_dbiterator_destroy(&old...".
406     		dns_dbiterator_destroy(&olddbiterator);
407     	}
408     	dns_db_detach(&olddb);
409     
410     	return (ISC_R_SUCCESS);
411     }