Fix NPE caused for non iceberg DESC formatted table queries

Author: tanishq-chugh

ql/src/java/org/apache/hadoop/hive/ql/ddl/table/info/desc/formatter/TextDescTableFormatter.java

@@ -151,7 +151,8 @@ private void addStatsData(DataOutputStream out, HiveConf conf, String columnPath
       statsData += "# ";
       metaDataTable.addRow(DescTableDesc.SCHEMA.split("#")[0].split(","));
     }
-    JsonNode FieldsNode = OBJECT_MAPPER.readTree(table.getParameters().get("current-schema")).get("fields");
+    JsonNode FieldsNode = isIcebergTable ?
+        OBJECT_MAPPER.readTree(table.getParameters().get("current-schema")).get("fields") : null;
     for (FieldSchema column : columns) {
       List<String> values = new ArrayList<>(List.of(ShowUtils.extractColumnValues(column, needColStats,
           getColumnStatisticsObject(column.getName(), column.getType(), columnStats), histogramEnabled)));