virtio/net.rs: ran rustfmt 0.3.4-nightly
virtio/net.rs: ran rustfmt 0.3.4-nightly

Signed-off-by: Alexandru Agache <69826f943dd6ae0c808126caf67f094b6aee96c2@amazon.com>

firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker