shill: 64-bit fixes: integer sizes for printf

BUG=chromium-os:23594
TEST=Rerun unit tests (on x86 and amd64)

Change-Id: Ia4f300e9feea7fb568145f158cb49d3cad4123ca
Reviewed-on: https://gerrit.chromium.org/gerrit/12283
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Commit-Ready: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
diff --git a/dhcp_config_unittest.cc b/dhcp_config_unittest.cc
index 47e1f5c..9a89c90 100644
--- a/dhcp_config_unittest.cc
+++ b/dhcp_config_unittest.cc
@@ -209,7 +209,7 @@
         NewCallback(&callback_test, &UpdateCallbackTest::Callback));
     config_->ProcessEventSignal(kReasons[r], conf);
     EXPECT_TRUE(callback_test.called()) << message;
-    EXPECT_EQ(base::StringPrintf("%u.0.0.0", r), config_->properties().address)
+    EXPECT_EQ(base::StringPrintf("%zu.0.0.0", r), config_->properties().address)
         << message;
   }
 }