gfs2: Clean up freeing struct gfs2_sbd

Add a free_sbd function for freeing a struct gfs2_sbd.  Use that for
freeing a super-block descriptor, either directly or via kobject_put.
Free sd_lkstats inside the kobject release function: that way,
gfs2_put_super will no longer leak sd_lkstats.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
diff --git a/fs/gfs2/super.h b/fs/gfs2/super.h
index c5f42f0..9d49eaa 100644
--- a/fs/gfs2/super.h
+++ b/fs/gfs2/super.h
@@ -44,6 +44,8 @@ extern void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh,
 extern int gfs2_statfs_sync(struct super_block *sb, int type);
 extern void gfs2_freeze_func(struct work_struct *work);
 
+extern void free_sbd(struct gfs2_sbd *sdp);
+
 extern struct file_system_type gfs2_fs_type;
 extern struct file_system_type gfs2meta_fs_type;
 extern const struct export_operations gfs2_export_ops;