... changes

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/2273042
diff --git a/test/bench/pidigits.go b/test/bench/pidigits.go
index dcfb502..55da379 100644
--- a/test/bench/pidigits.go
+++ b/test/bench/pidigits.go
@@ -100,7 +100,7 @@
 
 func printf(s string, arg ...interface{}) {
 	if !*silent {
-		fmt.Printf(s, arg)
+		fmt.Printf(s, arg...)
 	}
 }