syz-repro-automation: logfile and dir flags

Add logfile and dir flags to specify whether or not argument is a log
file or directory. Also refactored accordingly.

BUG=b:193906330
TEST=go run repro.go

Change-Id: I74150286c5121b291c9fba15ac4f3e5e3e677de1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3057632
Commit-Queue: Grant Hugh <ghugh@chromium.org>
Tested-by: Grant Hugh <ghugh@chromium.org>
Reviewed-by: Zubin Mithra <zsm@chromium.org>
2 files changed