tehuti: return -EFAULT on copy_to_user errors

copy_to_user() returns the number of bytes remaining but we want to
return a negative error code here.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/tehuti.c

@@ -646,7 +646,7 @@ static int bdx_ioctl_priv(struct net_device *ndev, struct ifreq *ifr, int cmd)
 		error = copy_from_user(data, ifr->ifr_data, sizeof(data));
 		if (error) {
 			pr_err("cant copy from user\n");
-			RET(error);
+			RET(-EFAULT);
 		}
 		DBG("%d 0x%x 0x%x\n", data[0], data[1], data[2]);
 	}
@@ -665,7 +665,7 @@ static int bdx_ioctl_priv(struct net_device *ndev, struct ifreq *ifr, int cmd)
 		    data[2]);
 		error = copy_to_user(ifr->ifr_data, data, sizeof(data));
 		if (error)
-			RET(error);
+			RET(-EFAULT);
 		break;
 
 	case BDX_OP_WRITE: