Some clippy fixes. #1816

Job	Run time
Address Sanitizer	12m 21s
Clippy	1m 47s
Test Rust nightly	10m 8s
Test Rust beta	9m 13s
Test Rust stable	8m 49s
Test macOS	32m 33s
Docs	40s
Examples Rust nightly	4m 36s
Examples Rust beta	4m 10s
Test Windows (msvc)	12m 23s
Examples Rust stable	4m 17s
Format	11s
Examples macOS	5m 35s
Examples Windows (gnu)	6m 10s
Test forcing wrapper generation	6m 18s
Examples Windows (msvc)	4m 35s
Outdated	9s
	2h 3m 55s

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