virtio-devices: seccomp: Add seccomp filters for rng thread

This patch enables the seccomp filters for the rng worker thread.

Partially fixes: #925

Signed-off-by: Bo Chen <chen.bo@intel.com>

virtio-devices/src/lib.rs

@@ -129,4 +129,5 @@ pub enum Error {
     EpollHander(String),
     NoMemoryConfigured,
     NetQueuePair(::net_util::NetQueuePairError),
+    ApplySeccompFilter(seccomp::Error),
 }