ci: Update for buildkite environment

* Tweak west_setup:
  - log `west update` to a file to reduce noise in log
  - use `west forall` + `git reset` to make sure files are checked out
    (this is to handle a possible module cache)
* Output when we start sanity_check.  Add a banner for when we run
  sanity_check so it's a bit easier to find in console logs

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>

scripts/ci/run_ci.sh

@@ -146,7 +146,8 @@ function west_setup() {
 	pushd ..
 	if [ ! -d .west ]; then
 		west init -l ${git_dir}
-		west update
+		west update 1> west.update.log
+		west forall -c 'git reset --hard HEAD'
 	fi
 	popd
 }
@@ -268,6 +269,8 @@ if [ -n "$main_ci" ]; then
 	tail -n +2 test_file_1.txt > test_file_1_in.txt
 	cat test_file_3.txt test_file_2_in.txt test_file_1_in.txt > test_file.txt
 
+	echo "+++ run sanitycheck"
+
 	# Run a subset of tests based on matrix size
 	${sanitycheck} ${sanitycheck_options} --load-tests test_file.txt \
 		--subset ${matrix}/${matrix_builds} --retry-failed 3