Commit 00eacd66 ("ext3: make ext3 mount default to barrier=1") changed
the default barrier mount option for ext3.  The documentation needs to
be updated, so this patch does that.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NJan Kara <jack@suse.cz>