Release data sooner

mpi/src/mpi_failure_tolerance/starpu_mpi_checkpoint.c

@@ -78,8 +78,8 @@ void _starpu_mpi_push_cp_ack_recv_cb(struct _starpu_mpi_cp_ack_arg_cb* arg)
 void _recv_internal_dup_ro_cb(void* _args)
 {
 	struct _starpu_mpi_cp_ack_arg_cb* arg = (struct _starpu_mpi_cp_ack_arg_cb*) _args;
-	_starpu_mpi_store_data_and_send_ack_cb(arg);
 	starpu_data_release(arg->copy_handle);
+	_starpu_mpi_store_data_and_send_ack_cb(arg);
 }
 
 void _recv_cp_external_data_cb(void* _args)