[SCSI] zfcp: Fail erp after timeout

After a timeout notification, do not try to run the erp strategy.
Return from the erp with "failed" to possibly trigger a retry.

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