s390/qeth: delay netdevice registration

Re-order the code flow a bit so that all initial HW setup is done before
putting the netdevice into play. For a netdevice that hasn't been
registered before, we also don't need to re-enable its HW features or
check for recovery actions.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>