libnvdimm, namespace: Drop the repeat assignment for variable dev->parent

The variable dev-parent is assigned twice with the same &nd_region->dev.
I think we could drop the second one.
Signed-off-by: GuangZhe Fu <fugz1@lenovo.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/nvdimm/namespace_devs.c

@@ -2099,7 +2099,6 @@ static struct device *nd_namespace_pmem_create(struct nd_region *nd_region)
 		return NULL;
 	}
 	dev_set_name(dev, "namespace%d.%d", nd_region->id, nspm->id);
-	dev->parent = &nd_region->dev;
 	dev->groups = nd_namespace_attribute_groups;
 	nd_namespace_pmem_set_resource(nd_region, nspm, 0);