[gnome-boxes] assistant: Use explicit .begin for async calls

[Felipe Borges <felipeborges src gnome org>]

commit a079e5cebbe6505a9067ed14b37ae8103bf24856
Author: Felipe Borges <felipeborges gnome org>
Date:   Tue Dec 14 14:34:38 2021 +0100

    assistant: Use explicit .begin for async calls
    
    Implicit .begin is deprecated in Vala.

 src/assistant/preparation-page.vala | 2 +-
 src/assistant/vm-assistant.vala     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/assistant/preparation-page.vala b/src/assistant/preparation-page.vala
index c62dda5c..6839d44c 100644
--- a/src/assistant/preparation-page.vala
+++ b/src/assistant/preparation-page.vala
@@ -54,7 +54,7 @@ public async override void next () {
             return;
         }
 
-        setup (media, os);
+        setup.begin (media, os);
     }
 
     public async void prepare (InstallerMedia media) {
diff --git a/src/assistant/vm-assistant.vala b/src/assistant/vm-assistant.vala
index 184f854e..8fc5d3ea 100644
--- a/src/assistant/vm-assistant.vala
+++ b/src/assistant/vm-assistant.vala
@@ -100,7 +100,7 @@ private async void on_next_button_clicked () {
     private void do_preparation (Object object) {
         pages.set_visible_child (preparation_page);
 
-        preparation_page.setup (object as InstallerMedia);
+        preparation_page.setup.begin (object as InstallerMedia);
     }
 
     [GtkCallback]