analysis/app: show the geomean

Change-Id: I5c1363125998acf7d28692aa94ddfbef148577c2
Reviewed-on: https://go-review.googlesource.com/38094
Reviewed-by: Quentin Smith <quentin@golang.org>
diff --git a/analysis/app/compare.go b/analysis/app/compare.go
index 3e47fca..c60cefd 100644
--- a/analysis/app/compare.go
+++ b/analysis/app/compare.go
@@ -286,7 +286,9 @@
 
 	var buf bytes.Buffer
 	// Compute benchstat
-	c := new(benchstat.Collection)
+	c := &benchstat.Collection{
+		AddGeoMean: true,
+	}
 	for _, g := range groups {
 		c.AddResults(g.Q, g.results)
 	}