[GFS2] fs/gfs2/ops_fstype.c:fill_super_meta(): fix NULL dereference

Don't dereference new->s_root when we do know it's NULL.

Spotted by the Coverity checker.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/ops_fstype.c

@@ -794,7 +794,7 @@ static int fill_super_meta(struct super_block *sb, struct super_block *new,
 		fs_err(sdp, "can't get root dentry\n");
 		error = -ENOMEM;
 		iput(inode);
-	}
+	} else
 		new->s_root->d_op = &gfs2_dops;
 
 	return error;