Use the the generic VFS attr flags where appropriate instead of open
coding them to the same values.

Patch provided by Eric Sandeen.

SGI-PV: 960868
SGI-Modid: xfs-linux-melb:xfs-kern:28033a
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>