chore: Remove unused Diplay impl for MachineConfig

This Display implementation is unused, and furthermore just a duplicate
of the automatically generated `Debug` implementation (which is a rust
anti-pattern).

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

src/vmm/src/vmm_config/machine_config.rs

@@ -1,6 +1,6 @@
 // Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
-use std::fmt::{self, Debug};
+use std::fmt::Debug;
 
 use serde::{de, Deserialize, Serialize};
 
@@ -52,17 +52,6 @@ impl Default for MachineConfig {
     }
 }
 
-impl fmt::Display for MachineConfig {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(
-            f,
-            "{{ \"vcpu_count\": {:?}, \"mem_size_mib\": {:?}, \"smt\": {:?}, \"cpu_template\": \
-             {:?}, \"track_dirty_pages\": {:?} }}",
-            self.vcpu_count, self.mem_size_mib, self.smt, self.cpu_template, self.track_dirty_pages
-        )
-    }
-}
-
 /// Struct used in PATCH `/machine-config` API call.
 /// Used to update `VmConfig` in `VmResources`.
 /// This struct mirrors all the fields in `MachineConfig`.