CLJS-225: fix warning about undeclared Var in cljs.reader
CLJS-225: fix warning about undeclared Var in cljs.reader

The reason was a typo in read-keyword; the resulting function worked
because cljs.core/keyword's binary variant currently delegates to the
unary variant anyway.

mstang/clojurescript,mstang/clojurescript,mstang/clojurescript