[GFS2] Set d_ops for root inode

Well, I managed to track down the bug in gfs2 that was causing
my grief.  Below is a patch for the problem.  Please incorporate
as you see fit.  Or should I say: as you see git.

The problem was basically that you never set d_ops for the root
inode, so the wrong hash algorithm was being used.  But only for
the root directory.  Turns out that if I used subdirectories, it
used the proper hash and my files were found just fine.
Signed-off-by: NRobert S Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

fs/gfs2/ops_fstype.c

@@ -40,6 +40,8 @@
 #define DO 0
 #define UNDO 1
 
+extern struct dentry_operations gfs2_dops;
+
 static struct gfs2_sbd *init_sbd(struct super_block *sb)
 {
 	struct gfs2_sbd *sdp;
@@ -357,6 +359,7 @@ static int init_sb(struct gfs2_sbd *sdp, int silent, int undo)
 		error = -ENOMEM;
 		iput(inode);
 	}
+	sb->s_root->d_op = &gfs2_dops;
 out:
 	gfs2_glock_dq_uninit(&sb_gh);
 	return error;