ACPI: NFIT: Fix unlock on error in scrub_show()

We change the locking in this function and forgot to update this error
path so we are accidentally still holding the "dev->lockdep_mutex".

Fixes: 87a30e1 ("driver-core, libnvdimm: Let device subsystems add local lockdep coverage")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: 5.3+ <stable@vger.kernel.org> # 5.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/nfit/core.c

@@ -1322,7 +1322,7 @@ static ssize_t scrub_show(struct device *dev,
 	nfit_device_lock(dev);
 	nd_desc = dev_get_drvdata(dev);
 	if (!nd_desc) {
-		device_unlock(dev);
+		nfit_device_unlock(dev);
 		return rc;
 	}
 	acpi_desc = to_acpi_desc(nd_desc);