libertas: fix error return code in if_cs_probe()

Fix to return -ENODEV in the unknown model error handling
case instead of 0, as done elsewhere in this function.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/if_cs.c

@@ -902,6 +902,7 @@ static int if_cs_probe(struct pcmcia_device *p_dev)
 	if (card->model == MODEL_UNKNOWN) {
 		pr_err("unsupported manf_id 0x%04x / card_id 0x%04x\n",
 		       p_dev->manf_id, p_dev->card_id);
+		ret = -ENODEV;
 		goto out2;
 	}