Use ref for SvTreeList's parent SvListView

Follow-up of commit 74816dd6

Change-Id: I246df80586c8fc60efc68b5deeb865cbfcd0da13
Reviewed-on: https://gerrit.libreoffice.org/64762
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

include/vcl/treelist.hxx

@@ -67,7 +67,7 @@ class VCL_DLLPUBLIC SvTreeList final
 {
     friend class        SvListView;
 
-    SvListView* const   mpOwnerListView;
+    SvListView&         mrOwnerListView;
     sal_uLong           nEntryCount;
 
     Link<SvTreeListEntry*, SvTreeListEntry*>  aCloneLink;
@@ -131,7 +131,7 @@ class VCL_DLLPUBLIC SvTreeList final
 public:
 
                         SvTreeList() = delete;
-                        SvTreeList(SvListView*);
+                        SvTreeList(SvListView&);
                         ~SvTreeList();
 
     void                Broadcast(

vcl/source/treelist/treelist.cxx

@@ -58,8 +58,8 @@ struct SvListView::Impl
 };
 
 
-SvTreeList::SvTreeList(SvListView* listView) :
-    mpOwnerListView(listView),
+SvTreeList::SvTreeList(SvListView& listView) :
+    mrOwnerListView(listView),
     mbEnableInvalidate(true)
 {
     nEntryCount = 0;
@@ -79,7 +79,7 @@ void SvTreeList::Broadcast(
     sal_uLong nPos
 )
 {
-    mpOwnerListView->ModelNotification(nActionId, pEntry1, pEntry2, nPos);
+    mrOwnerListView.ModelNotification(nActionId, pEntry1, pEntry2, nPos);
 }
 
 // an entry is visible if all parents are expanded
@@ -1075,7 +1075,7 @@ std::pair<SvTreeListEntries::iterator, SvTreeListEntries::iterator>
 SvListView::SvListView()
     : m_pImpl(new Impl(*this))
 {
-    pModel.reset(new SvTreeList(this));
+    pModel.reset(new SvTreeList(*this));
     m_pImpl->InitTable();
 }