[SCSI] zfcp: erp failed status bit will not be set

It will not be necessary to set the erp failed status bit
in case a SCSI device is removed by the SCSI mid layer.
In the case a SCSI device is unavailable for a short time
(15 to 20 seconds) a FCP unit will not get on-line again.

Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>