Posix shell doesn't support '=='
Change-Id: Icbdc4204f4c07d806e721fa39f96694c4df00e8d
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81285
Reviewed-by: Patrick Georgi <patrick@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
