s390/qeth: clean up error path in qeth_core_probe_device()

qeth_core_free_card() is meant to be the counterpart of
qeth_alloc_card() - but unfortunately was also picked as the place
to free the QDIO queues.

This gets messy when qeth_core_probe_device() fails during
qeth_add_dbf_entry(). At this point the card->qdio.state is not initialized
yet, so qeth_free_qdio_queues() ends up operating on uninitialized data.

Luckily for now, the whole qeth_card struct is zero-allocated and the value
of the QETH_QDIO_UNINITIALIZED enum is 0 as well. So there's no real impact
from this bug at the moment, it's just really fragile.

Clean this up by moving the qeth_free_qdio_queues() call up one level in
the hierarchy. This way it doesn't get called from the error path.

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