renaming_4: gofix -r everything/but/src/pkg

R=rsc
CC=golang-dev
https://golang.org/cl/5338043
diff --git a/doc/codewalk/markov.go b/doc/codewalk/markov.go
index 959c2b1..cb28eb0 100644
--- a/doc/codewalk/markov.go
+++ b/doc/codewalk/markov.go
@@ -50,8 +50,8 @@
 	"flag"
 	"fmt"
 	"io"
+	"math/rand"
 	"os"
-	"rand"
 	"strings"
 	"time"
 )