[SCSI] zfcp: Fix opening of wka ports

Running two wka_port_get calls in parallel could issue two open_port
requests, overwriting the port handle. Don't issue an open_port
for the state PORT_OPENING, and only read the data from GOOD
responses.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index d024442..48bfd30 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -1584,6 +1584,7 @@
 		wka_port->status = ZFCP_WKA_PORT_OFFLINE;
 		break;
 	case FSF_PORT_ALREADY_OPEN:
+		break;
 	case FSF_GOOD:
 		wka_port->handle = header->port_handle;
 		wka_port->status = ZFCP_WKA_PORT_ONLINE;