Fix bug in v0 refactor script

Review URL: https://codereview.chromium.org/1054113003

Cr-Commit-Position: refs/heads/master@{#323641}
diff --git a/tools/telemetry/refactor b/tools/telemetry/refactor
index e2c0f6c..e8c144b 100755
--- a/tools/telemetry/refactor
+++ b/tools/telemetry/refactor
@@ -107,7 +107,7 @@
       _WriteImports(updated_file, import_group)
       import_group = []
 
-      Updated_file.write(line)
+      updated_file.write(line)
 
   if import_group:
     _WriteImports(updated_file, import_group)