cargo: Update to the latest kvm-ioctls version

We need to rely on the latest kvm-ioctls version to benefit from the
recent addition of unregister_ioevent(), allowing us to detach a
previously registered eventfd to a PIO or MMIO guest address.

Because of this update, we had to modify the current constraint we had
on the vmm-sys-util crate, using ">= 0.1.1" instead of being strictly
tied to "0.2.0".

Once the dependency conflict resolved, this commit took care of fixing
build issues caused by recent modification of kvm-ioctls relying on
EventFd reference instead of RawFd.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

arch/src/x86_64/regs.rs

@@ -84,7 +84,9 @@ pub fn setup_msrs(vcpu: &VcpuFd) -> Result<()> {
     msrs.nmsrs = entry_vec.len() as u32;
 
     vcpu.set_msrs(msrs)
-        .map_err(Error::SetModelSpecificRegisters)
+        .map_err(Error::SetModelSpecificRegisters)?;
+
+    Ok(())
 }
 
 /// Configure base registers for a given CPU.