If it is not cleared and the number of strings is fewer than last iteration, the match[3] will keep the last value, which actually should be empty. Add assert to make sure the level is a legal value. BUG=b:222038278 Change-Id: If14e0923fbb1648d83784eb5dc1411c93227db5a Signed-off-by: Zheng Bao <fishbaozi@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/62482 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Felix Held <felix-coreboot@felixheld.de>