clippy: resolve build errors for Rust 1.78

[eugkoira]

Resolving a couple of clippy errors when building with Rust 1.78:

• https://rust-lang.github.io/rust-clippy/master/index.html\#/unnecessary_get_then_check
• https://rust-lang.github.io/rust-clippy/master/index.html\#/unnecessary_to_owned
• https://rust-lang.github.io/rust-clippy/master/index.html\#/to_string_trait_impl

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.