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: Ib478d9f09641d4ab942f0b326d2d2238131be6e0
Reviewed-on: https://gerrit.chromium.org/gerrit/11219
Reviewed-by: Nick Sanders <nsanders@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: Jay Kim <yongjaek@chromium.org>
Tested-by: Paul Taysom <taysom@google.com>
Commit-Ready: Paul Taysom <taysom@google.com>
1 file changed