hypervisor, arch: Fix warnings introduced in hypervisor crate

This commit fixes some warnings introduced in the previous
hyperviosr crate PR.Removed some unused variables from arch/aarch64
module.

Signed-off-by: Muminul Islam <muislam@microsoft.com>

vmm/src/cpu.rs

@@ -586,6 +586,7 @@ impl VcpuState {
 }
 
 impl CpuManager {
+    #[allow(unused_variables)]
     pub fn new(
         config: &CpusConfig,
         device_manager: &Arc<Mutex<DeviceManager>>,