sdio: handle cis end marker in link field

Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

drivers/mmc/core/sdio_cis.c

@@ -227,6 +227,10 @@ static int sdio_read_cis(struct mmc_card *card, struct sdio_func *func)
 		if (ret)
 			break;
 
+		/* a size of 0xff also means we're done */
+		if (tpl_link == 0xff)
+			break;
+
 		this = kmalloc(sizeof(*this) + tpl_link, GFP_KERNEL);
 		if (!this)
 			return -ENOMEM;