Fix the out-of-bounds read issue found by Coverity. TEST=none Signed-off-by: Jason Nien <finaljason@gmail.com> Change-Id: I01e134cb6b025bf7cb5030cd9378297d7f6df509 Reported-by: Coverity (CID:1376956) Reviewed-on: https://review.coreboot.org/c/coreboot/+/58803 Reviewed-by: Felix Held <felix-coreboot@felixheld.de> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>