Add fio version to terse output

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fio.h b/fio.h
index 04963cd..df0daf6 100644
--- a/fio.h
+++ b/fio.h
@@ -502,6 +502,7 @@
 extern int is_backend;
 extern int nr_clients;
 extern int log_syslog;
+extern const char fio_version_string[];
 extern const fio_fp64_t def_percentile_list[FIO_IO_U_LIST_MAX_LEN];
 
 extern struct thread_data *threads;