Update ocfs2_should_update_atime() to understand the MNT_RELATIME flag and
to test against mtime / ctime accordingly.

[akpm@osdl.org: cleanups]
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Valerie Henson <val_henson@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>