build: Fix beta clippy issue (derive_partial_eq_without_eq)

warning: you are deriving `PartialEq` and can implement `Eq`
  --> vmm/src/serial_manager.rs:59:30
   |
59 | #[derive(Debug, Clone, Copy, PartialEq)]
   |                              ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#derive_partial_eq_without_eq

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

block_util/src/lib.rs

@@ -138,7 +138,7 @@ impl ExecuteError {
     }
 }
 
-#[derive(Clone, Copy, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum RequestType {
     In,
     Out,