entry: remove AdditionalData2

The 'AdditionalData2' property was a temporary addition to ease the
transition from an array to a dictionary for the additional data.
All users have been migrated to use the dictionary style and from the
'AdditionalData' property, so the '2' property can be removed.

Tested: Loaded an existing log database and observed dbus objects
are created successfully and with the 'AdditionalData2' field missing.
Created a new event with `log-create` CLI and observed new entry is
created successfully in dbus.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ica3a9e5730eca8a7cf7755b769189347220e1639
diff --git a/elog_serialize.cpp b/elog_serialize.cpp
index 80cb27a..414fb4b 100644
--- a/elog_serialize.cpp
+++ b/elog_serialize.cpp
@@ -31,7 +31,7 @@
 template <class Archive>
 void save(Archive& a, const Entry& e, const std::uint32_t /*version*/)
 {
-    a(e.id(), e.severity(), e.timestamp(), e.message(), e.additionalData2(),
+    a(e.id(), e.severity(), e.timestamp(), e.message(), e.additionalData(),
       e.associations(), e.resolved(), e.version(), e.updateTimestamp(),
       e.eventId(), e.resolution());
 }
@@ -109,7 +109,6 @@
     e.timestamp(timestamp, true);
     e.message(message, true);
     e.additionalData(additionalData, true);
-    e.additionalData2(additionalData, true);
     e.sdbusplus::server::xyz::openbmc_project::logging::Entry::resolved(
         resolved, true);
     e.associations(associations, true);