I have migrated all my products from Magento 1.9 to 2.0. All the products url's are ending with .html like html.html
sample link: http://www/domain.com/condenser-microphone.html.html
You can truncate url-rewrite table again and reindex to see the result
UPDATE url_rewrite SET request_path = REPLACE(request_path, '.html.html', '.html');
Then clear the cache.