fix bug induced by change in api (pair fn instead of update fn)

README.md

@@ -44,7 +44,7 @@ Add this dependency to your project:
 `avg` is a reducing fn to compute the arithmetic mean. `juxt` is used to compute several reducing fns at once.
 ```clj
 => (into {} (x/by-key odd? (x/reduce (x/juxt + x/avg))) (range 256))
-{0 [16256 127], 1 [16384 128]}
+{false [16256 127], true [16384 128]}
 ```
 
 ## License

src/net/cgrand/xforms.clj

@@ -83,7 +83,7 @@
           ([acc] (clj/reduce (fn [acc krf] (krf acc)) acc (vals (persistent! @m))))
           ([acc x]
             (let [k (kfn x)
-                  krf (or (get @m k) (doto (xform (make-rf x)) (->> (vswap! m assoc! k))))
+                  krf (or (get @m k) (doto (xform (make-rf k)) (->> (vswap! m assoc! k))))
                   acc (krf acc (vfn x))]
               (when (reduced? acc)
                 (vswap! m assoc! k noprf))