net/mlx4_en: remove fallback after kzalloc_node()

kzalloc_node(..., GFP_KERNEL, node) will attempt to allocate
memory as close as possible to the node.

There is no need to fallback to kzalloc() if this has failed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>