s390/qeth: don't disable address events during initialization

A newly initialized device is disabled for address events, there's no
need to explicitly disable them.

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