src/pkg/[n-z]*: gofix -r error -force=error

R=golang-dev, bsiegert, iant
CC=golang-dev
https://golang.org/cl/5294074
diff --git a/src/pkg/time/tick.go b/src/pkg/time/tick.go
index 852bae9..92f9eb8 100644
--- a/src/pkg/time/tick.go
+++ b/src/pkg/time/tick.go
@@ -5,7 +5,7 @@
 package time
 
 import (
-	"os"
+	"errors"
 	"sync"
 )
 
@@ -160,7 +160,7 @@
 // ns must be greater than zero; if not, NewTicker will panic.
 func NewTicker(ns int64) *Ticker {
 	if ns <= 0 {
-		panic(os.NewError("non-positive interval for NewTicker"))
+		panic(errors.New("non-positive interval for NewTicker"))
 	}
 	c := make(chan int64, 1) //  See comment on send in tickerLoop
 	t := &Ticker{