update .clang-format header inclusion order

Added the header inclusion order to the .clang-format file generated
these changes.

Change-Id: Ia31b21d7ea451cac0309828006bc17c27cbd5bd5
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/exception/sdbus_error.cpp b/test/exception/sdbus_error.cpp
index c1d8baa..40d88ee 100644
--- a/test/exception/sdbus_error.cpp
+++ b/test/exception/sdbus_error.cpp
@@ -1,12 +1,14 @@
+#include <systemd/sd-bus.h>
+
 #include <cstdlib>
-#include <gtest/gtest.h>
 #include <sdbusplus/exception.hpp>
 #include <sdbusplus/test/sdbus_mock.hpp>
 #include <stdexcept>
 #include <string>
-#include <systemd/sd-bus.h>
 #include <utility>
 
+#include <gtest/gtest.h>
+
 // Needed for constructor error testing
 extern sdbusplus::SdBusImpl sdbus_impl;