nvcc compiler warning: calling a __host__ function from a __host__ __device__ function is not allowed

[ndellingwood]

Sample warning message (nvcc 7.5):

kokkos/core/src/KokkosExp_View.hpp(1352): warning: calling a host function from a host device function is not allowed

      detected during:
        instantiation of "Kokkos::Experimental::View<DataType, Properties...>::View(Kokkos::Experimental::View<DataType, Properties...>::pointer_type, size_t, size_t, size_t, size_t, size_t, size_t, size_t, size_t) [with DataType=int *, Properties=<Kokkos::Serial>]"

/ascldap/users/ndellin/kokkos/core/unit_test/TestViewMapping.hpp(622): here

        instantiation of "void Test::test_view_mapping<ExecSpace>() [with ExecSpace=Kokkos::Serial]"

/ascldap/users/ndellin/kokkos/core/unit_test/TestSerial.cpp(112): here

[ndellingwood]

Fix submitted as issue 181