Fix Style/RedundantEach for non-chained each_ calls

[fatkodima]

Style/RedundantEach fails for [1, 2, 3].each with no method block_type? for nil.

And incorrectly detects as offense the following:

build_enumerator(outer: [[1, 2, 3].each]).each

[RDeckard]

Great, thanks! 🙏

And moreover, shouldn't the documentation be corrected this way:

This cop is unsafe, as it can produce false positives if the receiver is not an Enumerable Enumerator.

Because for example an array, which is an Enumerable but not an Enumerator, does not implement #with_object or #with_index.

[koic]

Thanks!

[koic]

@RDeckard Good catch. I've fixed that typo in the master.