Use ext4 format for stateful partition

This is final step in ext4 conversion. We have been running with
the ext4 file system but ext3 format for several weeks. This changes
uses the ext4 format for the stateful partition.

BUG=chromium-os:20012
TEST=Ran ext4 on all platforms

Change-Id: Iac104517976ff531afa81994d9a6c8241229e4d6
Reviewed-on: https://gerrit.chromium.org/gerrit/11218
Reviewed-by: Richard Barnette <jrbarnette@chromium.org>
Tested-by: Paul Taysom <taysom@google.com>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Commit-Ready: Paul Taysom <taysom@google.com>
1 file changed