remove unnecessary use of _checkForMethod

The remaining uses of `_checkForMethod` are to support the lazy-list extension or to conform to the [Fantasy Land Specification][1]:

```console
$ ack '=.*checkForMethod' | sed "s:.*'\(.*\)'.*:\1:" | sort
chain
filter
map
skip
tail
take
takeWhile
```


[1]: https://github.com/fantasyland/fantasy-land