swig: prefer typedef to using

According to swig3.0. the 'using' keyword
in type aliasing is not fully supported yet.

* spot/ltsmin/ltsmin.hh: here.

spot/ltsmin/ltsmin.hh

@@ -29,7 +29,7 @@ namespace spot
 {
   struct spins_interface;
   class cspins_iterator;
-  using cspins_state = int*;
+  typedef int* cspins_state;
 
   class SPOT_API ltsmin_model final
   {