GFS2: Use UUID field in generic superblock

The VFS superblock structure now has a UUID field, so we can use that
in preference to the UUID field in the GFS2 superblock now.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index 748ccb5..e20eab3 100644
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -81,7 +81,8 @@
 
 static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
 {
-	const u8 *uuid = sdp->sd_sb.sb_uuid;
+	struct super_block *s = sdp->sd_vfs;
+	const u8 *uuid = s->s_uuid;
 	buf[0] = '\0';
 	if (!gfs2_uuid_valid(uuid))
 		return 0;
@@ -616,7 +617,8 @@
 		       struct kobj_uevent_env *env)
 {
 	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
-	const u8 *uuid = sdp->sd_sb.sb_uuid;
+	struct super_block *s = sdp->sd_vfs;
+	const u8 *uuid = s->s_uuid;
 
 	add_uevent_var(env, "LOCKTABLE=%s", sdp->sd_table_name);
 	add_uevent_var(env, "LOCKPROTO=%s", sdp->sd_proto_name);