[JFFS2] Fix data CRC checking on NOR flash.

	BUG_ON(tn->csize == 0);

	if (!jffs2_is_writebuffered(c))

		goto adj_acc;

	/* Calculate how many bytes were already checked */

	ofs = ref_offset(ref) + sizeof(struct jffs2_raw_inode);

	len = ofs % c->wbuf_pagesize;

	if (likely(len))

		len = c->wbuf_pagesize - len;

	len = tn->csize;

	if (len >= tn->csize) {

	if (jffs2_is_writebuffered(c)) {

		int adj = ofs % c->wbuf_pagesize;

		if (likely(adj))

			adj = c->wbuf_pagesize - adj;

		if (adj >= tn->csize) {

			dbg_readinode("no need to check node at %#08x, data length %u, data starts at %#08x - it has already been checked.\n",

				      ref_offset(ref), tn->csize, ofs);

			goto adj_acc;

		}

	ofs += len;

	len = tn->csize - len;

		ofs += adj;

		len -= adj;

	}

	dbg_readinode("check node at %#08x, data length %u, partial CRC %#08x, correct CRC %#08x, data starts at %#08x, start checking from %#08x - %u bytes.\n",

		ref_offset(ref), tn->csize, tn->partial_crc, tn->data_crc, ofs - len, ofs, len);