Capture all boost::system::error_codes by ref

Capturing these possibly overloaded values by reference can avoid a copy
in some cases, and it's good to be consistent.

This change was made automatically by grep/sed.

Tested: Code compiles.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Iafeaca2a5dc52f39753b5a3880419d6bc943f81b
diff --git a/redfish-core/lib/update_service.hpp b/redfish-core/lib/update_service.hpp
index 7c8ce01..ddb46f6 100644
--- a/redfish-core/lib/update_service.hpp
+++ b/redfish-core/lib/update_service.hpp
@@ -575,7 +575,7 @@
 
     // Set the requested image apply time value
     crow::connections::systemBus->async_method_call(
-        [asyncResp](const boost::system::error_code ec) {
+        [asyncResp](const boost::system::error_code& ec) {
         if (ec)
         {
             BMCWEB_LOG_ERROR << "D-Bus responses error: " << ec;