cxgb4: Do not set net_device::dev_id to VI index

net_device::dev_id should not be used merely to indicate a VI index,
as it affects the way the local part of IPv6 addresses is normally
generated.

This field was intended for use where multiple devices may share a
single assigned MAC address and need to have different IPv6 addresses.
T4 VIs each have their own MAC address.

Signed-off-by: Ben Hutchings <[e-mail]>
Acked-by: Dimitris Michailidis <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c

···
 		p->lport = j;
 		p->rss_size = rss_size;
 		memcpy(adap->port[i]->dev_addr, addr, ETH_ALEN);
-		adap->port[i]->dev_id = j;
 
 		ret = ntohl(c.u.info.lstatus_to_modtype);
 		p->mdio_addr = (ret & FW_PORT_CMD_MDIOCAP) ?