[SCSI] zfcp: Do not try "forced close" when port is already closed

When the port is already "physically closed" try the reopen instead.
There is no way to send a "physically close" to an already closed
port.

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>