[gnome-commander/Implement_CppCheck_suggestions] Use static_cast instead of C-style cast

[Uwe Scholz <uwescholz src gnome org>]

commit 3734ae0ddfbc4452b22661ecb284ea934d985db9
Author: Uwe Scholz <u scholz83 gmx de>
Date:   Tue Mar 12 22:24:36 2019 +0100

    Use static_cast instead of C-style cast

 src/dialogs/gnome-cmd-chown-dialog.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/dialogs/gnome-cmd-chown-dialog.cc b/src/dialogs/gnome-cmd-chown-dialog.cc
index c1c74873..fd327368 100644
--- a/src/dialogs/gnome-cmd-chown-dialog.cc
+++ b/src/dialogs/gnome-cmd-chown-dialog.cc
@@ -179,9 +179,9 @@ static void gnome_cmd_chown_dialog_init (GnomeCmdChownDialog *dialog)
 
 GtkWidget *gnome_cmd_chown_dialog_new (GList *files)
 {
-    g_return_val_if_fail (files != NULL, NULL);
+    g_return_val_if_fail (files != nullptr, nullptr);
 
-    GnomeCmdChownDialog *dialog = (GnomeCmdChownDialog *) g_object_new (GNOME_CMD_TYPE_CHOWN_DIALOG, NULL);
+    auto *dialog = static_cast<GnomeCmdChownDialog*> (g_object_new (GNOME_CMD_TYPE_CHOWN_DIALOG, nullptr));
     dialog->priv->files = gnome_cmd_file_list_copy (files);
     GnomeCmdFile *f = GNOME_CMD_FILE (dialog->priv->files->data);