filter: bytecode already in the list should go before

filter: bytecode already in the list should go before

Background
==========
This `seqnum` (sequence number) feature is currently unused. It was
designed so that the session daemon could tell the tracer the order in
which the bytecode should be run.

Issue
=====
The current implementation of the session daemon doesn't use this
feature so there is only ever a single bytecode to execute per callsite.

During work on an upcoming feature uses this `seqnum` became useful and
it was realized that the current bytecode linking code would reverse the
order in which the bytecode were executed when all bytecodes have the
same `seqnum` value.

This is due to the fact that the `cds_list_for_each_entry_reverse` loops
until it finds a `seqnum` smaller than the new one.

So if all bytecodes have the same `seqnum`, the new bytecode will be
added at the beginning of the list.

This is not technically a problem since it's the session daemon's job to
set the sequence number if it wants a particular ordering. Even
considering that, we found it counterintuitive that new bytecodes are
added at the beginning of the list in those cases.

Solution
========
This commit makes it so that on equality, the insertion is done after
the existing bytecodes.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ie323b3ff5df346f222e22abfb9bbad6c5b7e4a27