The devm_memremap() function never returns NULL.  It returns error
pointers.
Fixes: cdc3d2abf438 ("usb: typec: ucsi: acpi: Map the mailbox with memremap()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
        }
 
        ua->base = devm_memremap(&pdev->dev, res->start, resource_size(res), MEMREMAP_WB);
-       if (!ua->base)
-               return -ENOMEM;
+       if (IS_ERR(ua->base))
+               return PTR_ERR(ua->base);
 
        ret = guid_parse(UCSI_DSM_UUID, &ua->guid);
        if (ret)