Fix clippy warnings and add clippy to pipeline

[h7x4]

Clippy already seemed to be included in the CI workflow, it was just never executed.

[coveralls]

Pull Request Test Coverage Report for Build 5964992405

Details

• 18 of 33 (54.55%) changed or added relevant lines in 6 files are covered.
• 6 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.03%) to 65.961%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/host.rs	0	1	0.0%
src/cdc.rs	1	4	25.0%
src/device.rs	10	21	47.62%

Files with Coverage Reduction	New Missed Lines	%
../../../.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/task/join.rs	1	90.48%
src/device.rs	5	58.28%

Totals
Change from base Build 5952485612:	-0.03%
Covered Lines:	1527
Relevant Lines:	2315

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💛 - Coveralls