buildman: Ignore conflicting tags

Tags like Series-version are normally expected to appear once, and with a
unique value. But buildman doesn't actually look at these tags. So ignore
conflicts.

This allows bulidman to build a branch containing multiple patman series.

Reported-by: Steve Rae <srae@broadcom.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
3 files changed