Include transfer size in the clat/slat measurements

It's useful to know the block size that matches the given latency, so
add that to the end.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/log.c b/log.c
index 6913357..6d5e68d 100644
--- a/log.c
+++ b/log.c
@@ -471,8 +471,10 @@
 	}
 
 	for (i = 0; i < log->nr_samples; i++) {
-		fprintf(f, "%lu, %lu, %u\n", log->log[i].time, log->log[i].val,
-						log->log[i].ddir);
+		fprintf(f, "%lu, %lu, %u, %u\n", log->log[i].time,
+						log->log[i].val,
+						log->log[i].ddir,
+						log->log[i].bs);
 	}
 
 	fclose(f);