Removed Useless Argument Check
diff --git a/checkout.go b/checkout.go
index a511306..f5822c9 100644
--- a/checkout.go
+++ b/checkout.go
@@ -119,9 +119,6 @@
 
 //export checkoutProgressCallback
 func checkoutProgressCallback(path *C.char, completed_steps, total_steps C.size_t, data unsafe.Pointer) int {
-	if data == nil {
-		return 0
-	}
 	opts := pointerHandles.Get(data).(*CheckoutOpts)
 	if opts.ProgressCallback == nil {
 		return 0