Fixup reporting for !runtime data directions

Got broken with the group reporting, the minimum time and bw
should only be accounted for data directions where actual
work has happened. Otherwise they are pretty much guarenteed
to be 0.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/stat.c b/stat.c
index e5e626c..681d5cb 100644
--- a/stat.c
+++ b/stat.c
@@ -741,37 +741,29 @@
 	}
 
 	for (i = 0; i < nr_ts; i++) {
-		unsigned long long rbw, wbw;
+		unsigned long long bw;
 
 		ts = &threadstats[i];
 		rs = &runstats[ts->groupid];
 
-		if (ts->runtime[0] < rs->min_run[0] || !rs->min_run[0])
-			rs->min_run[0] = ts->runtime[0];
-		if (ts->runtime[0] > rs->max_run[0])
-			rs->max_run[0] = ts->runtime[0];
-		if (ts->runtime[1] < rs->min_run[1] || !rs->min_run[1])
-			rs->min_run[1] = ts->runtime[1];
-		if (ts->runtime[1] > rs->max_run[1])
-			rs->max_run[1] = ts->runtime[1];
+		for (j = 0; j < 2; j++) {
+			if (!ts->runtime[j])
+				continue;
+			if (ts->runtime[j] < rs->min_run[j] || !rs->min_run[j])
+				rs->min_run[j] = ts->runtime[j];
+			if (ts->runtime[j] > rs->max_run[j])
+				rs->max_run[j] = ts->runtime[j];
 
-		rbw = wbw = 0;
-		if (ts->runtime[0])
-			rbw = ts->io_bytes[0] / (unsigned long long) ts->runtime[0];
-		if (ts->runtime[1])
-			wbw = ts->io_bytes[1] / (unsigned long long) ts->runtime[1];
+			bw = 0;
+			if (ts->runtime[j])
+				bw = ts->io_bytes[j] / (unsigned long long) ts->runtime[j];
+			if (bw < rs->min_bw[j])
+				rs->min_bw[j] = bw;
+			if (bw > rs->max_bw[j])
+				rs->max_bw[j] = bw;
 
-		if (rbw < rs->min_bw[0])
-			rs->min_bw[0] = rbw;
-		if (wbw < rs->min_bw[1])
-			rs->min_bw[1] = wbw;
-		if (rbw > rs->max_bw[0])
-			rs->max_bw[0] = rbw;
-		if (wbw > rs->max_bw[1])
-			rs->max_bw[1] = wbw;
-
-		rs->io_kb[0] += ts->io_bytes[0] >> 10;
-		rs->io_kb[1] += ts->io_bytes[1] >> 10;
+			rs->io_kb[j] += ts->io_bytes[j] >> 10;
+		}
 	}
 
 	for (i = 0; i < groupid + 1; i++) {