Remove assert checking for non zero page size in wxDataViewCtrl.

This assert seems to be quite useless and can be triggered if a key is
(perhaps accidentally) sent to a small (e.g. not yet fully laid out)
wxDataViewCtrl window.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@78146 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/datavgen.cpp

@@ -3627,10 +3627,6 @@ void wxDataViewMainWindow::OnChar( wxKeyEvent &event )
         return;
     }
 
-    // don't use m_linesPerPage directly as it might not be computed yet
-    const int pageSize = GetCountPerPage();
-    wxCHECK_RET( pageSize, wxT("should have non zero page size") );
-
     switch ( event.GetKeyCode() )
     {
         case WXK_RETURN:
@@ -3756,11 +3752,11 @@ void wxDataViewMainWindow::OnChar( wxKeyEvent &event )
             break;
 
         case WXK_PAGEUP:
-            OnVerticalNavigation(event, -(pageSize - 1));
+            OnVerticalNavigation(event, -(GetCountPerPage() - 1));
             break;
 
         case WXK_PAGEDOWN:
-            OnVerticalNavigation(event, +(pageSize - 1));
+            OnVerticalNavigation(event, +(GetCountPerPage() - 1));
             break;
 
         default: