pch_phub: Report error writing MAC back to user

Signed-off-by: Alexander Stein <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/pch_phub.c

···
 	u8 mac[ETH_ALEN];
 	ssize_t rom_size;
 	struct pch_phub_reg *chip = dev_get_drvdata(dev);
+	int ret;
 
 	if (!mac_pton(buf, mac))
 		return -EINVAL;
···
 	if (!chip->pch_phub_extrom_base_address)
 		return -ENOMEM;
 
-	pch_phub_write_gbe_mac_addr(chip, mac);
+	ret = pch_phub_write_gbe_mac_addr(chip, mac);
 	pci_unmap_rom(chip->pdev, chip->pch_phub_extrom_base_address);
+	if (ret)
+		return ret;
 
 	return count;
 }