[XFS] XFS propagates MS_NOATIME through two levels internally but doesn't

actually use it.  Kill this dead code.	Signed-off-by: Christoph Hellwig
<hch@lst.de>

SGI-PV: 904196
SGI-Modid: xfs-linux-melb:xfs-kern:25086a

Signed-off-by: Nathan Scott <nathans@sgi.com>