[JFFS2] Fix return value check for mtd->point() in check_node_data()

If we ask it to map 'len' bytes of the device, don't compare against 
some other number and whine that it's different. That's a little silly.
Signed-off-by: Alexey Korolev <akorolev@infradead.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

fs/jffs2/readinode.c

@@ -64,7 +64,7 @@ static int check_node_data(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info
 	 * adding and jffs2_flash_read_end() interface. */
 	if (c->mtd->point) {
 		err = c->mtd->point(c->mtd, ofs, len, &retlen, &buffer);
-		if (!err && retlen < tn->csize) {
+		if (!err && retlen < len) {
 			JFFS2_WARNING("MTD point returned len too short: %zu instead of %u.\n", retlen, tn->csize);
 			c->mtd->unpoint(c->mtd, buffer, ofs, retlen);
 		} else if (err)