tests: cleanup go_anon_fn_variable_call_test.v (#13786)

vlib/v/tests/go_anon_fn_variable_call_test.v

@@ -1,18 +1,35 @@
-fn sum(a int, b int) int {
-	// Simply proxy the function into an anonymous function for demo purposes
-	sum_func := fn (a int, b int) int {
+fn sum1(a int, b int) int {
+	sum_func1 := fn (a int, b int) int {
 		return a + b
 	}
+	sum_func2 := sum_func1
 
-	// and run it concurrently
-	g := go sum_func(a, b)
+	g := go sum_func2(a, b)
+
+	result := g.wait()
+	return result
+}
+
+fn add(a int, b int) int {
+	return a + b
+}
+
+fn sum2(a int, b int) int {
+	sum_func1 := add
+	sum_func2 := sum_func1
+
+	g := go sum_func2(a, b)
 
 	result := g.wait()
 	return result
 }
 
 fn test_go_anon_fn_variable_call() {
-	ret := sum(22, 33)
-	println(ret)
-	assert ret == 55
+	ret1 := sum1(22, 33)
+	println(ret1)
+	assert ret1 == 55
+
+	ret2 := sum2(2, 3)
+	println(ret2)
+	assert ret2 == 5
 }