neg_multiply should show a suggestion

[kpcyrd]

Description

  --> worker/src/proc.rs:78:19
   |
78 |         let pid = pid as i32 * -1;
   |                   ^^^^^^^^^^^^^^^
   |
   = note: `#[warn(clippy::neg_multiply)]` on by default
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#neg_multiply

There's no suggestion how this should be done and the docs just say:

It’s more readable to just negate.

but don't show how this is supposed to be done.

I had to google "how to negate an integer" and clippy should just suggest this:

let pid = -(pid as i32);

Version

rustc 1.57.0 (f1edd0429 2021-11-29)
binary: rustc
commit-hash: f1edd0429582dd29cccacaf50fd134b05593bd9c
commit-date: 2021-11-29
host: x86_64-unknown-linux-gnu
release: 1.57.0
LLVM version: 13.0.0

Additional Labels

No response

[Gh0stm4chine]

@rustbot claim

[kpcyrd]

@Gh0stm4chine Thank you!