ACPI: NFIT: Fix comparison to '-ENXIO'

Initial value of rc is '-ENXIO', and we should
use the initial value to check it.
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/nfit/core.c

@@ -1564,7 +1564,7 @@ static ssize_t format1_show(struct device *dev,
 					le16_to_cpu(nfit_dcr->dcr->code));
 			break;
 		}
-		if (rc != ENXIO)
+		if (rc != -ENXIO)
 			break;
 	}
 	mutex_unlock(&acpi_desc->init_mutex);