[SCSI] zfcp: Remove two FIXME comments

On a link down, the adapter reopen is not strictly necessary, but it
helps flushing pending requests as quickly as possible. Add a comment
mentioning this.

qdio returning a problem on the response queue is an unlikely event.
The recovery mentioned in the comment might resolve it, so implement
it. This also has the advantage that it creates an entry in the
recovery trace to see if and when this is occurring.

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>