jffs2: call jffs2_write_super from jffs2_sync_fs

The call to ->write_super from __sync_filesystem will go away, so make
sure jffs2 performs the same actions from inside ->sync_fs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index f7bfd3a..07a22ca 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -74,6 +74,8 @@
 {
 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 
+	jffs2_write_super(sb);
+
 	mutex_lock(&c->alloc_sem);
 	jffs2_flush_wbuf_pad(c);
 	mutex_unlock(&c->alloc_sem);