virtio-devices: Simplify virtio device reset

Rather than having to give and return the ioeventfd used for a device
clone them each time. This will make it simpler when we start handling
the driver enabling fewer queues than advertised by the device.

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

virtio-devices/src/vsock/device.rs

@@ -475,7 +475,7 @@ where
         Ok(())
     }
 
-    fn reset(&mut self) -> Option<(Arc<dyn VirtioInterrupt>, Vec<EventFd>)> {
+    fn reset(&mut self) -> Option<Arc<dyn VirtioInterrupt>> {
         self.common.reset()
     }