xfs: use bt_nr_sectors in xfs_dax_translate_range

Only ranges inside the file system can be translated, and the file system
can be smaller than the containing device.

Fixes: f4ed9303 ("xfs: don't shut down the filesystem for media failures beyond end of log")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>