No real changes, just replace -1 with wxNOT_FOUND in wxBookCtrl code.

Make the code consistently use wxNOT_FOUND instead of -1 everywhere.

See #12622.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65930 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/cocoa/notebook.mm

@@ -301,7 +301,7 @@ int wxNotebook::GetSelection() const
 {
     NSTabViewItem *selectedItem = [GetNSTabView() selectedTabViewItem];
     if(!selectedItem)
-        return -1;
+        return wxNOT_FOUND;
     return [GetNSTabView() indexOfTabViewItem:selectedItem];
 }