Bugfix in forward update with modeling on.

Fixes an issue with reducing branch cts in the encoder causing
a drop in performance. The bug was introduced in a previous
clean up patch.

Test: Went back to the offending patch, applied this same fix
to it, and checked that results are identical to the parent
of that patch.

Change-Id: I0bad8e2d930235d0284300fcebf836ceb56f2498