kaweth: fix oops upon failed memory allocation

Just return an error upon failure.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/kaweth.c

@@ -1009,6 +1009,7 @@ static int kaweth_probe(
 	struct net_device *netdev;
 	const eth_addr_t bcast_addr = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
 	int result = 0;
+	int rv = -EIO;
 
 	dev_dbg(dev,
 		"Kawasaki Device Probe (Device number:%d): 0x%4.4x:0x%4.4x:0x%4.4x\n",
@@ -1049,6 +1050,10 @@ static int kaweth_probe(
 		/* Download the firmware */
 		dev_info(dev, "Downloading firmware...\n");
 		kaweth->firmware_buf = (__u8 *)__get_free_page(GFP_KERNEL);
+		if (!kaweth->firmware_buf) {
+			rv = -ENOMEM;
+			goto err_free_netdev;
+		}
 		if ((result = kaweth_download_firmware(kaweth,
 						      "kaweth/new_code.bin",
 						      100,
@@ -1203,7 +1208,7 @@ static int kaweth_probe(
 err_free_netdev:
 	free_netdev(netdev);
 
-	return -EIO;
+	return rv;
 }
 
 /****************************************************************