Setting rust-analyzer.checkOnSave.command to "clippy" causes silent failures if clippy is not installed for the current toolchain

[semicoleon]

rust-analyzer versions:
- ce86534 2021-10-10 nightly
- 4b7675f 2021-10-04 stable

rust toolchains
- stable-x86_64-pc-windows-msvc unchanged - rustc 1.55.0 (c8dfcfe04 2021-09-06)
- nightly-x86_64-pc-windows-msvc unchanged - rustc 1.57.0-nightly (54bb4fec6 2021-10-08)

This appears to work for basically any crate, I can reproduce it with a new empty crate by adding a trait to main.rs and implementing it incorrectly

pub trait Trait {
    fn method();
}

// This impl should produce an error
impl Trait for () {}

fn main() {}

If clippy is not installed RA appears to indicate there are no errors. Some basic syntax errors still show up. Installing clippy with rustup component add clippy or setting rust-analyzer.checkOnSave.command back to "check" both resolve the issue.

I think RA should show some kind of error when the command isn't found. It's possible there's an error in a log somewhere but I wasn't able to track it down quickly if so.