bitstream-debug: Merge queue_pop and queue_push

The bitstream_queue_pop and bitstream_queue_push functions were
implemented twice each, one implementation for CONFIG_DAALA_EC being set
and for it not being set. This could cause issues with debugging since
there's two potential paths, meaning breakpoints and edits need to be
inserted twice.

The functions were already minimally different, so this patch merges the
implementation pairs to simplify the code.

Change-Id: I37cdd96470f0ae41b25dc28da50e2c7a1b9af01e