logfs: fix sync

Rather self-explanatory.

Signed-off-by: Joern Engel <joern@logfs.org>
diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c
index af78b6e..755a92e 100644
--- a/fs/logfs/inode.c
+++ b/fs/logfs/inode.c
@@ -387,8 +387,7 @@
 
 static int logfs_sync_fs(struct super_block *sb, int wait)
 {
-	/* FIXME: write anchor */
-	logfs_super(sb)->s_devops->sync(sb);
+	logfs_write_anchor(sb);
 	return 0;
 }