linux/virtio: add missing initialization of scatter-gather lists
linux/virtio: add missing initialization of scatter-gather lists

RX and TX scatterlists should be initialized before passing them to
virtqueue APIs, otherwise those APIs will detect unexpected list chaining
is not expected (virtio_net netmap adapter uses one virtio descriptor per
packet).

Signed-off-by: Nikita Kalyazin <82c94e8210876770e26693ca4e87eab4d9598ab2@samsung.com>
Reviewed-by: Vincenzo Maffione <9c61b7c5ebb3b288da4fe59954d7c41958e8c3d4@gmail.com>

luigirizzo/netmap,luigirizzo/netmap,luigirizzo/netmap,luigirizzo/netmap,luigirizzo/netmap