10411 loader: dev_net: correct net_open's interpretation of params
Review Request #1480 - Created Feb. 16, 2019 and submitted
https://reviews.freebsd.org/D19206 net_open previously casted the first vararg to a char * and this was half-OK: at first, it is passed to netif_open, which would cast it back to the struct devdesc * that it really is and use it properly. It is then strdup()d and used as the netdev_name, which is objectively wrong. Correct it so that the first vararg is properly casted to a struct devdesc * and the netdev_name gets set properly to make it more clear at a glance that it's not doing something horribly wrong.