[SCSI] zfcp: wait until adapter is finished with ERP during auto-port

In some situations the auto port attachment task is started
before the ERP is finished. To prevent this unwanted situation
we wait until the adapter is up and running before we start our work.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>