loplugin:useuniqueptr in FileDialogHelper_Impl

Change-Id: I91f831be99284b61385cee42dc59efd0cf7f45ba
Reviewed-on: https://gerrit.libreoffice.org/48406Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

sfx2/source/dialog/filedlghelper.cxx

@@ -1141,7 +1141,7 @@ FileDialogHelper_Impl::~FileDialogHelper_Impl()
         Application::RemoveUserEvent( mnPostUserEventId );
     mnPostUserEventId = nullptr;
 
-    delete mpGraphicFilter;
+    mpGraphicFilter.reset();
 
     if ( mbDeleteMatcher )
         delete mpMatcher;
@@ -1841,7 +1841,7 @@ void FileDialogHelper_Impl::addGraphicFilter()
         return;
 
     // create the list of filters
-    mpGraphicFilter = new GraphicFilter;
+    mpGraphicFilter.reset( new GraphicFilter );
     sal_uInt16 i, j, nCount = mpGraphicFilter->GetImportFormatCount();
 
     // compute the extension string for all known import filters

sfx2/source/dialog/filedlgimpl.hxx

@@ -50,7 +50,7 @@ namespace sfx2
         std::vector< css::beans::StringPair >   maFilters;
 
         SfxFilterMatcher*           mpMatcher;
-        GraphicFilter*              mpGraphicFilter;
+        std::unique_ptr<GraphicFilter> mpGraphicFilter;
         FileDialogHelper*           mpAntiImpl;
         VclPtr<vcl::Window>         mpPreferredParentWindow;