New clippy lint

[Wojtek242]

https://github.com/rust-pcap/pcap/runs/7822954049?check_suite_focus=true

error: you are deriving `PartialEq` and can implement `Eq`
  --> src/lib.rs:91:17
   |
91 | #[derive(Debug, PartialEq)]
   |                 ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
   |
   = note: `-D clippy::derive-partial-eq-without-eq` implied by `-D warnings`
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#derive_partial_eq_without_eq