scsi: lpfc: Fix lpfc_wwn_set return code check

When I reversed the patch to re-add the lpfc_soft_wwn parameter feature,
it re-added code that had a long-standing bug. (that's what I get I
guess :)

As Dan Carpenter pointed out - error checks looked at wrong polarity.  0
is success, -errno is failure. Updated checks.
Signed-off-by: James Smart <james.smart@broadcom.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_attr.c

@@ -2150,7 +2150,7 @@ lpfc_soft_wwpn_store(struct device *dev, struct device_attribute *attr,
 	phba->soft_wwn_enable = 0;
 
 	rc = lpfc_wwn_set(buf, cnt, wwpn);
-	if (!rc) {
+	if (rc) {
 		/* not able to set wwpn, unlock it */
 		phba->soft_wwn_enable = 1;
 		return rc;
@@ -2231,7 +2231,7 @@ lpfc_soft_wwnn_store(struct device *dev, struct device_attribute *attr,
 		return -EINVAL;
 
 	rc = lpfc_wwn_set(buf, cnt, wwnn);
-	if (!rc) {
+	if (rc) {
 		/* Allow wwnn to be set many times, as long as the enable
 		 * is set. However, once the wwpn is set, everything locks.
 		 */