Rather than use an embedded String inside the MultiQueueSupport error
value use two different values to differentiate the two cases.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
By moving the code for opening the TAP device into a shared location we
are starting to remove the requirement for the vhost-user-net backend to
depend on the virtio-devices crate which in of itself depends on many
other crates that are not necessary for the backend to function.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>