net: aquantia: Fix error return code in aq_pci_probe()

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

Fixes: 23ee07ad

 ("net: aquantia: Cleanup pci functions module")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>