vmm: cleanup &Mutex parameters

In [0] we refactored some Arc<Mutex<T>> parameters to &Mutex<T>> to
satisfy clippy's needless_pass_by_value lint. Nevertheless, this is also
not so idiomatic, so as a follow-up, we put the responsibility to lock
objects to the caller side (only where this is not strictly needed by
the callee).

While on it, I also tried to pass vm_config directly into
pre_create_console_devices() which would clean up some code, but then
we have interleaving mutable and immutable borrows of the Vmm, which
are denied by the borrow checker.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com

vmm/src/vm.rs

@@ -2390,16 +2390,15 @@ impl Vm {
         for vcpu in vcpus {
             let guest_memory = &self.memory_manager.lock().as_ref().unwrap().guest_memory();
             let boot_setup = entry_point.map(|e| (e, guest_memory));
+            let mut vcpu = vcpu.lock().unwrap();
             self.cpu_manager
                 .lock()
                 .unwrap()
-                .configure_vcpu(&vcpu, boot_setup)
+                .configure_vcpu(&mut vcpu, boot_setup)
                 .map_err(Error::CpuManager)?;
 
             #[cfg(target_arch = "aarch64")]
-            vcpu.lock()
-                .unwrap()
-                .set_gic_redistributor_addr(redist_addr[2], redist_addr[3])
+            vcpu.set_gic_redistributor_addr(redist_addr[2], redist_addr[3])
                 .map_err(Error::CpuManager)?;
         }