PCI/switchtec: Replace ENOTSUPP with EOPNOTSUPP

ENOTSUPP is not a SUSV4 error code, and the following checkpatch.pl
warning will be given for new patches which still use ENOTSUPP.

    WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP

See the link below for the discussion.

  https://lore.kernel.org/netdev/20200511165319.2251678-1-kuba@kernel.org/

Replace ENOTSUPP with EOPNOTSUPP to align with future patches which will
be using EOPNOTSUPP.

Link: https://lore.kernel.org/r/20211014141859.11444-5-kelvin.cao@microchip.comSigned-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/switch/switchtec.c

@@ -376,7 +376,7 @@ static ssize_t field ## _show(struct device *dev, \
 		return io_string_show(buf, &si->gen4.field, \
 				      sizeof(si->gen4.field)); \
 	else \
-		return -ENOTSUPP; \
+		return -EOPNOTSUPP; \
 } \
 \
 static DEVICE_ATTR_RO(field)
@@ -668,7 +668,7 @@ static int ioctl_flash_info(struct switchtec_dev *stdev,
 		info.flash_length = ioread32(&fi->gen4.flash_length);
 		info.num_partitions = SWITCHTEC_NUM_PARTITIONS_GEN4;
 	} else {
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 	}
 
 	if (copy_to_user(uinfo, &info, sizeof(info)))
@@ -876,7 +876,7 @@ static int ioctl_flash_part_info(struct switchtec_dev *stdev,
 		if (ret)
 			return ret;
 	} else {
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 	}
 
 	if (copy_to_user(uinfo, &info, sizeof(info)))
@@ -1611,7 +1611,7 @@ static int switchtec_init_pci(struct switchtec_dev *stdev,
 	else if (stdev->gen == SWITCHTEC_GEN4)
 		part_id = &stdev->mmio_sys_info->gen4.partition_id;
 	else
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	stdev->partition = ioread8(part_id);
 	stdev->partition_count = ioread8(&stdev->mmio_ntb->partition_count);