mpi: fix variable name and datatype

mpi/src/starpu_mpi.c

@@ -239,7 +239,7 @@ void starpu_mpi_data_register_comm(starpu_data_handle_t data_handle, starpu_mpi_
 		mpi_data->node_tag.comm = MPI_COMM_WORLD;
 		data_handle->mpi_data = mpi_data;
 #if defined(STARPU_USE_MPI_MPI)
-		_starpu_mpi_tag_data_register(data_handle, tag);
+		_starpu_mpi_tag_data_register(data_handle, data_tag);
 #endif
 		_starpu_mpi_cache_data_init(data_handle);
 		_starpu_data_set_unregister_hook(data_handle, _starpu_mpi_data_clear);

mpi/src/starpu_mpi_private.h

@@ -290,7 +290,7 @@ LIST_TYPE(_starpu_mpi_req,
 PRIO_LIST_TYPE(_starpu_mpi_req, prio)
 
 struct _starpu_mpi_req *_starpu_mpi_isend_irecv_common(starpu_data_handle_t data_handle,
-						       int srcdst, int data_tag, MPI_Comm comm,
+						       int srcdst, starpu_mpi_tag_t data_tag, MPI_Comm comm,
 						       unsigned detached, unsigned sync, int prio, void (*callback)(void *), void *arg,
 						       enum _starpu_mpi_request_type request_type, void (*func)(struct _starpu_mpi_req *),
 						       enum starpu_data_access_mode mode,