ext4: fix quota inconsistency during orphan cleanup for read-only mounts

ext4: fix quota inconsistency during orphan cleanup for read-only mounts

BugLink: http://bugs.launchpad.net/bugs/1720154
commit 95f1fda47c9d8738f858c3861add7bf0a36a7c0b upstream.

Quota does not get enabled for read-only mounts if filesystem
has quota feature, so that quotas cannot updated during orphan
cleanup, which will lead to quota inconsistency.

This patch turn on quotas during orphan cleanup for this case,
make sure quotas can be updated correctly.

Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>