Bailing out on allocation error is nice, but we also need to tell the
ccwgroup core that creating the qeth groupdev failed.

Fixes: d3d1b205 ("s390/qeth: allocate netdevice early")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>