zephyr: twister: Pass return value through wrapper script
zephyr: twister: Pass return value through wrapper script

This is critical for causing the CQ to fail if Twister fails. Pass its
return value to sys.exit()

BUG=b:241967409
BRANCH=None
TEST=./twister -T /i-dont-exist; echo $?

Signed-off-by: Tristan Honscheid <1e17951ff5ffc8afe254954c03de64afef62fe52@google.com>
Change-Id: Id82c21e15399411c5ad7b4a2bc7501b62b366853
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3821375
Reviewed-by: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>
Commit-Queue: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec