clippy: fix lints

[xtqqczze]

https://rust-lang.github.io/rust-clippy/master/index.html#useless_borrows_in_formatting
https://rust-lang.github.io/rust-clippy/master/index.html#manual_assert_eq
https://rust-lang.github.io/rust-clippy/master/index.html#byte_char_slices

[cakebaker]

There are some more warnings from clippy 1.97.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/inotify-dir-recreate (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/tail-n0f (fails in this run but passes in the 'main' branch)
Note: The gnu test tests/printf/printf-surprise is now being skipped but was previously passing.

[cakebaker]

Thanks!