snmp_trap: send AdditionalData contents

The log messages often contain essential diagnostics information in a
key-value list in AdditionalData. Add it in space-separated form to the
SNMP trap.

Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Change-Id: I72a49a59e6f3f9fcc24a69b0752cbb7b122be940
2 files changed