adm80211: return an error if adm8211_alloc_rings() fails

We accidentally return success when adm8211_alloc_rings() fails but we
should preserve the error code.

Fixes: cc0b88cf5ecf ("[PATCH] Add adm8211 802.11b wireless driver")
Signed-off-by: Dan Carpenter <[e-mail]>
Signed-off-by: Kalle Valo <[e-mail]>

drivers/net/wireless/admtek/adm8211.c

···
 	priv->rx_ring_size = rx_ring_size;
 	priv->tx_ring_size = tx_ring_size;
 
-	if (adm8211_alloc_rings(dev)) {
+	err = adm8211_alloc_rings(dev);
+	if (err) {
 		printk(KERN_ERR "%s (adm8211): Cannot allocate TX/RX ring\n",
 		       pci_name(pdev));
 		goto err_iounmap;