Fixed warning

experimental/AcousticSolverTest.hpp

@@ -68,8 +68,8 @@ private:
 
   struct ReduceMin;
 
-  const long int m_nj;
-  const long int m_nr;
+  const size_t m_nj;
+  const size_t m_nr;
 
   Kokkos::View<double*> m_br;
   Kokkos::View<double*[2]> m_Ajr;