[GFS2] Remove support for unused and pointless flag

The ability to mark files for direct i/o access when opened
normally is both unused and pointless, so this patch removes
support for that feature.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --cc fs/gfs2/incore.h
Simple merge

diff --cc fs/gfs2/inode.c
Simple merge

diff --cc fs/gfs2/ops_file.c
Simple merge

diff --cc fs/gfs2/super.c
Simple merge

diff --cc fs/gfs2/sys.c
Simple merge