Drive-by cleanups to cargo-clippy. No functional change.
Drive-by cleanups to cargo-clippy. No functional change.

graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust