Auto merge of #8370 - smoelius:master, r=flip1995

Format `if_chain` invocations in clippy_utils

Not realizing it was [already obsolete](https://github.com/rust-lang/rust-clippy/pull/8360), I built a [tool to format inside `if_chain` invocations](https://crates.io/crates/rustfmt_if_chain).

This PR applies the tool to clippy_utils. (If you apply it to clippy_lints, the changes are extensive.)

Anyway, I'm making it known here in case anyone wants to use it while `if-let` chain support is developed for `rustfmt`. (There could be a few Clippy PRs between now and then, and IMHO, the code looks better with the `if_chain` invocations formatted.)

Cheers.

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changelog: none