Fix build issue related to boost asio

The previous commit has issue in the boost asio code and causes the
build error when host-bios-upgrade is enabled.

It was not caught by the repo CI because the repo CI build does not
enable the host-bios-upgrade config.

This patch fixes the issue by using the correct boost asio code.

Tested: Manually enable host-bios-upgrade in local CI and verify
        the build is fine.

Signed-off-by: Lei YU <yulei.sh@bytedance.com>
Change-Id: I224ee3a3706e83ec8ca9d6737d72a84f456d3b2f
diff --git a/activation.cpp b/activation.cpp
index 75d99ff..f9fbf87 100644
--- a/activation.cpp
+++ b/activation.cpp
@@ -6,6 +6,7 @@
 #include "serialize.hpp"
 
 #include <boost/asio/io_context.hpp>
+#include <boost/asio/post.hpp>
 #include <phosphor-logging/elog-errors.hpp>
 #include <phosphor-logging/elog.hpp>
 #include <phosphor-logging/log.hpp>
@@ -436,8 +437,8 @@
                 parent.versions.find(versionId)->second->version());
 
             // Delete the uploaded activation
-            getIOService().post([&parent = parent, versionId = versionId]() {
-                parent.erase(versionId);
+            boost::asio::post(getIOContext(), [this]() {
+                this->parent.erase(this->versionId);
             });
         }
         else if (newStateResult == "failed")