setup_board: --brick overrides --board.

This is necessary because --board has a default value, which may be
non-empty. Same logic was applied in (e.g.) cros_workon.

BUG=None
TEST=./setup_board --brick overrides --board value and emits a warning.

Change-Id: I485ad55f46764904851c7c3382257765d37ca6cb
Reviewed-on: https://chromium-review.googlesource.com/262044
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Bertrand Simonnet <bsimonnet@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
diff --git a/setup_board b/setup_board
index d963dac..d3cd0f9 100755
--- a/setup_board
+++ b/setup_board
@@ -265,8 +265,11 @@
 
 if [[ -z "${FLAGS_board}" ]] && [[ -z "${FLAGS_brick}" ]]; then
   die "--board or --brick required."
-elif [[ -n "${FLAGS_board}" ]] && [[ -n "${FLAGS_brick}" ]]; then
-  die "--board and --brick are incompatible."
+elif [[ -n "${FLAGS_brick}" ]]; then
+  # Override board name with the brick's friendly name (backward compatibility).
+  [[ -z "${FLAGS_board}" ]] || warn "--brick was used, ignoring --board value"
+  FLAGS_board="$(cros_brick_utils --friendly-name "${FLAGS_brick}")"
+  [[ -n "${FLAGS_board}" ]] || die_notrace
 fi
 
 get_board_and_variant "${FLAGS_board}" "${FLAGS_variant}" "${FLAGS_brick}"