[SCSI] iscsi class: sysfs group is_visible callout for session attrs

The iscsi class currently does not support writable sysfs
attrs for LLD sysfs settings. This patch converts the
iscsi class and driver's session attrs to use the attribute
container sysfs group and the sysfs group's is_visible callout
to be able to support readable or writable sysfs attrs.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index f8a1506..3022c15 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -138,8 +138,6 @@
 	.name			= DRIVER_NAME,
 	.caps			= CAP_FW_DB | CAP_SENDTARGETS_OFFLOAD |
 				  CAP_DATA_PATH_OFFLOAD,
-	.param_mask		= ISCSI_TARGET_NAME | ISCSI_TPGT |
-				  ISCSI_TARGET_ALIAS,
 	.host_param_mask	= ISCSI_HOST_HWADDRESS |
 				  ISCSI_HOST_IPADDRESS |
 				  ISCSI_HOST_INITIATOR_NAME,
@@ -173,6 +171,9 @@
 		switch (param) {
 		case ISCSI_PARAM_CONN_ADDRESS:
 		case ISCSI_PARAM_CONN_PORT:
+		case ISCSI_PARAM_TARGET_NAME:
+		case ISCSI_PARAM_TPGT:
+		case ISCSI_PARAM_TARGET_ALIAS:
 			return S_IRUGO;
 		default:
 			return 0;