Refactor the code and update description

examples/named-worker-with-on-fail-clause/named_worker_with_on_fail_clause.bal

@@ -1,31 +1,20 @@
 import ballerina/io;
 
-function getIndex(int[] values, int value) returns int|error {
-    int? index = values.indexOf(value);
-    if index is () {
-        return error("value not found");
-    } 
-
-    return index;
-}
-
 public function main() {
     int[] values = [2, 3, 4, 5];
     int value = 0;
 
     worker w1 {
         int index = check getIndex(values, value);
-        index -> w2;
+        index -> function;
     } on fail {
         // Handle the error thrown in the worker body.
-        -1 -> w2;
+        -1 -> function;
     }
 
-    worker w2 returns int|error:NoMessage {
-        int|error:NoMessage result = <- w1 | w1;
-        return result;
-    }
-
-    int|error:NoMessage result = wait w2;
+    int|error:NoMessage result = <- w1 | w1;
     io:println(result);
 }
+
+function getIndex(int[] values, int value) returns int|error =>
+    let int? index = values.indexOf(value) in index ?: error("value not found");

examples/named-worker-with-on-fail-clause/named_worker_with_on_fail_clause.md

@@ -1,6 +1,6 @@
 # Named worker with on fail clause
 
-The `on fail` clause can be incorporated into a named worker, to handle any errors that occur within the worker's body.
+The `on fail` clause can be used with a named worker, to handle any errors that occur within the worker's body.
 
 ::: code named_worker_with_on_fail_clause.bal :::