run_ci.sh: Fix what tests run with -l

If the local option (-l) was specified we were ignoring the results
of what_changed.py and always setting a "FULL" build.  Only explicitly
set a FULL run if we are building for a commit to the tree (local and
PR builds should respect the output of what_changed.py).

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>