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/include/vm_websocket.hpp b/include/vm_websocket.hpp
index 89270d9..fed3681 100644
--- a/include/vm_websocket.hpp
+++ b/include/vm_websocket.hpp
@@ -90,7 +90,7 @@
         doingWrite = true;
         pipeIn.async_write_some(
             inputBuffer->data(),
-            [this, self(shared_from_this())](boost::beast::error_code ec,
+            [this, self(shared_from_this())](const boost::beast::error_code& ec,
                                              std::size_t bytesWritten) {
             BMCWEB_LOG_DEBUG << "Wrote " << bytesWritten << "bytes";
             doingWrite = false;