Simplify the equlity check against 0
Simplify the equlity check against 0

Replace this with (zero? ...)

liuchang23/ring,ring-clojure/ring,ieure/ring,tchagnon/ring,kirasystems/ring,povloid/ring,orend/ring,ring-clojure/ring,siphiuel/ring,meowcakes/ring,suligap/ring