[SCSI] qla4xxx: Fix return code for qla4xxx_session_get_param.

While reading sysfs chap_in_idx and chap_out_idx attribute, if chap
authentication is not set we get an error as "Invalid argument".

Signed-off-by: Manish Rangankar <manish.rangankar@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/qla4xxx/ql4_os.c

@@ -1337,18 +1337,18 @@ static int qla4xxx_session_get_param(struct iscsi_cls_session *cls_sess,
 					      sess->password_in, BIDI_CHAP,
 					      &idx);
 		if (rval)
-			return -EINVAL;
+			len = sprintf(buf, "\n");
-
+		else
-		len = sprintf(buf, "%hu\n", idx);
+			len = sprintf(buf, "%hu\n", idx);
 		break;
 	case ISCSI_PARAM_CHAP_OUT_IDX:
 		rval = qla4xxx_get_chap_index(ha, sess->username,
 					      sess->password, LOCAL_CHAP,
 					      &idx);
 		if (rval)
-			return -EINVAL;
+			len = sprintf(buf, "\n");
-
+		else
-		len = sprintf(buf, "%hu\n", idx);
+			len = sprintf(buf, "%hu\n", idx);
 		break;
 	default:
 		return iscsi_session_get_param(cls_sess, param, buf);