RX rings can fit most of the time in a contiguous piece of memory,
so lets use kvzalloc_node/kvfree instead of vzalloc_node/vfree

Note that kvzalloc_node() automatically falls back to another node,
there is no need to do the fallback ourselves.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>