Add disk utilization to terse format output

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fio.1 b/fio.1
index ce08ff2..9f4b4a9 100644
--- a/fio.1
+++ b/fio.1
@@ -1176,6 +1176,11 @@
 .RE
 .RE
 .P
+Disk utilization (1 for each disk used):
+.RS
+.B name, read ios, write ios, read merges, write merges, read ticks, write ticks, read in-queue time, write in-queue time, disk utilization percentage
+.RE
+.P
 Error Info (dependent on continue_on_error, default off):
 .RS
 .B total # errors, first error code