[XFS] fix up per-device xfsbufd
SGI-PV: 947098
SGI-Modid: xfs-linux-melb:xfs-kern:203831a
Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
authored by Christoph Hellwig and committed by Nathan Scott da7f93e9 f5e596bb