make_dev_ssd: support devices using /dev/dm-1 as root device.

Some devices may use rootdev=/dev/dm-1 as root device (the default one was
dm-0, according to build scripts). Running make_dev_ssd.sh
--remove_rootfs_verification on these devices will fail changing rootdev kernel
command line, and cause people not able to re-mount root device as writable.

To support running make_dev_ssd on these devices, we want to change the rootdev
pattern to dm[0-9].

BUG=chromium:428041.
TEST=make_dev_ssd.sh --remove_rootfs_verification
BRANCH=none

Change-Id: Idfd251c58e7d39b0b80ec1fc68989c2f49bdd1b2
Reviewed-on: https://chromium-review.googlesource.com/226782
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
1 file changed