vm-virtio: Define a separate macro alias for ctrl queue devices

Now that we have factorized the common virtio pausable implementation,
it's cleaner to have a dedicated macro for control queue devices rather
than overload the macro prototype.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

vm-virtio/src/device.rs

@@ -203,8 +203,11 @@ macro_rules! virtio_pausable {
             }
         }
     };
+}
 
-    ($type:ident, $ctrl_q:expr) => {
+#[macro_export]
+macro_rules! virtio_ctrl_q_pausable {
+    ($type:ident) => {
         virtio_pausable_trait!($type);
 
         impl Pausable for $type {

vm-virtio/src/net.rs

@@ -583,6 +583,6 @@ impl VirtioDevice for Net {
     }
 }
 
-virtio_pausable!(Net, true);
+virtio_ctrl_q_pausable!(Net);
 impl Snapshotable for Net {}
 impl Migratable for Net {}

vm-virtio/src/vhost_user/net.rs

@@ -361,6 +361,6 @@ impl VirtioDevice for Net {
     }
 }
 
-virtio_pausable!(Net, true);
+virtio_ctrl_q_pausable!(Net);
 impl Snapshotable for Net {}
 impl Migratable for Net {}