cl: funcOf fix: call pyfunc multiple times

cl/_testpy/max/in.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"github.com/goplus/llgo/py"
+	"github.com/goplus/llgo/py/std"
+)
+
+func main() {
+	x := std.Max(py.Float(3.0), py.Float(9.0), py.Float(23.0), py.Float(100.0))
+	std.Print(x)
+
+	list := py.List(3.0, 9.0, 23.0, 100.0)
+	y := std.Max(std.Iter(list))
+	std.Print(y)
+}