build_image: Add custom suffix to output directory

Use --output_suffix flag to add custom suffix to output directory.

BUG=none
TEST= ./build_image --output_suffix="some_string" ... and check if output dir
is generated properly. Also check w/o --output_suffix if default works fine.

Change-Id: I8f88aab3cdebe4d013a8c5d3c889b25212ed907b
Signed-off-by: Waldemar Rymarkiewicz <ext.waldemar.rymarkiewicz@tieto.com>
Reviewed-on: https://chromium-review.googlesource.com/383151
Commit-Ready: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@gmail.com>
Tested-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@gmail.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed