There were a couple of references to using filter() that
needed to be replaced with list comprehensions as the return
values may be used repeatedly.

Bug: 1207012
Change-Id: Iae0abd38aeb186d6f7945f8c848c1f7312cb45bb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2890329Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@google.com>