xfs: don't shut down the filesystem for media failures beyond end of log

If the filesystem has an external log device on pmem and the pmem
reports a media error beyond the end of the log area, don't shut down
the filesystem because we don't use that space.

Cc: <stable@vger.kernel.org> # v6.0
Fixes: 6f643c57 ("xfs: implement ->notify_failure() for XFS")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>