net/mlx5e: fix error return code in mlx5e_alloc_rq()

Fix to return error code -ENOMEM from the kvzalloc_node() error handling
case instead of 0, as done elsewhere in this function.

Fixes: 069d1146

 ("net/mlx5e: RX, Enhance legacy Receive Queue memory scheme")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>