remove more clippy warnings

Author: GuillaumeGomez

src/lib.rs

@@ -149,6 +149,7 @@
 #![cfg_attr(feature = "cargo-clippy", allow(type_complexity))]
 #![cfg_attr(feature = "cargo-clippy", allow(transmute_ptr_to_ref))]
 #![cfg_attr(feature = "cargo-clippy", allow(trivially_copy_pass_by_ref))]
+#![cfg_attr(feature = "cargo-clippy", allow(derive_hash_xor_eq))]
 #![allow(deprecated)]
 
 extern crate libc;