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

include/wx/os2/notebook.h

@@ -61,7 +61,7 @@ public:
 
     //
     // Set the currently selected page, return the index of the previously
-    // selected one (or -1 on error)
+    // selected one (or wxNOT_FOUND on error)
     // NB: this function will _not_ generate wxEVT_NOTEBOOK_PAGE_xxx events
     //
     int      SetSelection(size_t nPage);