cherry-pick: factory_install: Fix sync timing issue on partition reloading.

Calling "sync" may need some extra time to schedule a sync system call.
We should leave some seconds before reloading partition table.

BUG=chrome-os-partner:9610
TEST=(x86) Zero /dev/sda, reboot, restart and completed factory install.

Change-Id: I3a6fb97653c7dbcda3dc076891d5d8c01635dc48
Original-Change-Id: I449e9d62ac9f17850842025a1a210b8ff7c3a74c
Original-Reviewed-on: https://gerrit.chromium.org/gerrit/22568
Original-Tested-by: Hung-Te Lin <hungte@chromium.org>
Original-Commit-Ready: Hung-Te Lin <hungte@chromium.org>
Original-Reviewed-by: Rong Chang <rongchang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/23310
Tested-by: Dave Parker <dparker@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
1 file changed