Use suggestion for redundant_closure

[sanxiyn]

cc #442.

[Manishearth]

tests/compile-fail/eta.rs:15:27: 15:44 error: redundant closure found
tests/compile-fail/eta.rs:15     let c = Some(1u8).map(|a| {1+2; foo}(a));
                                                       ^~~~~~~~~~~~~~~~~
tests/compile-fail/eta.rs:4:9: 4:26 note: lint level defined here
tests/compile-fail/eta.rs:4 #![deny(redundant_closure)]
                                    ^~~~~~~~~~~~~~~~~
tests/compile-fail/eta.rs:15:27: 15:44 help: for further information visit https://github.com/Manishearth/rust-clippy/wiki#redundant_closure
tests/compile-fail/eta.rs:15:27: 15:44 help: remove closure as shown:
tests/compile-fail/eta.rs:       let c = Some(1u8).map({1+2; foo});

The last suggestion has an extra block.

Also, the help should be shown before the "for further information". Perhaps we should have a span_lint_and_then similar to span_lint_and_note which runs a closure at the correct time if the lint level is correct.

[sanxiyn]

Eh, an extra block is a pre-existing problem.

[Manishearth]

Wait, nvm, we need that anyway. Sorry about the confusion. Okay, could you handle the build failure and the ordering of the suggestion and wiki link?

[sanxiyn]

Done.

[Manishearth]

f() should only be run if the lint level is correct :)

[sanxiyn]

Oh. Fixed.

[Manishearth]

r+ pending travis