buffet: Remove unused URL

This variable was apparently never usd.

BUG=None
TEST=unittests

Change-Id: I06a79317a82946280d93c354db12df6bd2dedde3
Reviewed-on: https://chromium-review.googlesource.com/247503
Tested-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Christopher Wiley <wiley@chromium.org>

buffet/device_registration_info.cc

diff --git a/buffet/device_registration_info.cc b/buffet/device_registration_info.cc
index 07b902b..e947157 100644
--- a/buffet/device_registration_info.cc
+++ b/buffet/device_registration_info.cc
@@ -417,13 +417,6 @@
   if (!response->IsSuccessful())
     return std::string();
 
-  std::string auth_url = GetOAuthURL("auth", {
-    {"scope", "https://www.googleapis.com/auth/clouddevices"},
-    {"redirect_uri", "urn:ietf:wg:oauth:2.0:oob"},
-    {"response_type", "code"},
-    {"client_id", client_id_}
-  });
-
   url = GetServiceURL("registrationTickets/" + ticket_id_ +
                       "/finalize?key=" + api_key_);
   response = chromeos::http::SendRequestWithNoDataAndBlock(