GFS2: Banish struct gfs2_dinode_host

The final field in gfs2_dinode_host was the i_flags field. Thats
renamed to i_diskflags in order to avoid confusion with the existing
inode flags, and moved into the inode proper at a suitable location
to avoid creating a "hole".

At that point struct gfs2_dinode_host is no longer needed and as
promised (quite some time ago!) it can now be removed completely.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/ops_export.c b/fs/gfs2/ops_export.c
index 3a9b9b4..7fdeb14 100644
--- a/fs/gfs2/ops_export.c
+++ b/fs/gfs2/ops_export.c
@@ -213,7 +213,7 @@
 	}
 
 	error = -EIO;
-	if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) {
+	if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM) {
 		iput(inode);
 		goto fail;
 	}