[SCSI] zfcp: Fix adapter activation on link down

[SCSI] zfcp: Fix adapter activation on link down

If an exchange config is executed while the local link is down, the
request succeeds but the returned data is incomplete.  Proceeding with
the adapter activation is leading to an unpredictable behaviour (e.g.
kernel panic) caused by invalid values.  In such a scenario the
recommended ERP is to retry the action and wait for a link up event.
If the issue persists the activation has to fail.

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