s390: qeth driver fixes: atomic context fixups

    - qeth device functions were not callable
      in atomic context due to usage of wait_event_xxx operations in qeth.
      "schedule while atomic" message appeared and kernel dumped when
      removing slave from bond device.

Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>