fix compile

Signed-off-by: Kai Huang <[email protected]>

Author: ahkcs

core/src/main/java/org/opensearch/sql/expression/function/udf/binning/WidthBucketFunction.java

@@ -145,6 +145,12 @@ public static String calculateWidthBucket(
       Number numericMin = (Number) minValue;
       Number numericMax = (Number) maxValue;
 
+      double value = numericValue.doubleValue();
+      double min = numericMin.doubleValue();
+      double max = numericMax.doubleValue();
+
+      // Calculate range
+      double range = max - min;
       if (range <= 0) {
         return null;
       }