tvplanit: Fix memory leak in TVpExCanvas.DrawRotatedText (temporary font not destroyed).

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@4930 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/tvplanit/source/vpcanvasutils.pas

@@ -777,6 +777,7 @@ begin
   finally
     // Restore previously used font.
     FCanvas.Font.Assign(OldFont);
+    OldFont.Free;
   end;
 end;