[partition] Call update from init() in BootLoaderModel

- update() (might) add some extra rows for boot and root,
   which otherwise vanish temporarily when calling init.

src/modules/partition/core/BootLoaderModel.cpp

@@ -51,12 +51,12 @@ BootLoaderModel::~BootLoaderModel()
 void
 BootLoaderModel::init( const QList< Device* >& devices )
 {
+    cDebug() << "BLM::init with" << devices.count() << "devices" << rowCount() << "rows";
     beginResetModel();
     blockSignals( true );
 
     m_devices = devices;
-    clear();
-    createMbrItems();
+    updateInternal();
 
     blockSignals( false );
     endResetModel();
@@ -78,6 +78,7 @@ BootLoaderModel::createMbrItems()
 void
 BootLoaderModel::update()
 {
+    cDebug() << "BLM::update holds" << m_devices.count() << "devices" << rowCount() << "rows";
     beginResetModel();
     blockSignals( true );
     updateInternal();