Fixed a javadoc parameter.

Author: jmhofer

rxjava-core/src/main/java/rx/Observable.java

@@ -2745,7 +2745,7 @@ public R call(T0 t0, T1 t1, T2 t2, T3 t3) {
      *          The first source observable.
      * @param w1 
      *          The second source observable.
-     * @param combineLatestFunction 
+     * @param combineFunction 
      *          The aggregation function used to combine the source observable values.
      * @return A function from an observer to a subscription. This can be used to create an observable from.
      */