cxl: Refactor to use __free() for cxl_root allocation in cxl_find_nvdimm_bridge()

Use scope-based resource management __free() macro to drop the open coded
put_device() in cxl_find_nvdimm_bridge().

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/170449247353.3779673.5963704495491343135.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Author: davejiang

drivers/cxl/core/pmem.c

@@ -64,16 +64,14 @@ static int match_nvdimm_bridge(struct device *dev, void *data)
 
 struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_memdev *cxlmd)
 {
-	struct cxl_root *cxl_root = find_cxl_root(cxlmd->endpoint);
-	struct cxl_port *port;
+	struct cxl_root *cxl_root __free(put_cxl_root) =
+		find_cxl_root(cxlmd->endpoint);
 	struct device *dev;
 
 	if (!cxl_root)
 		return NULL;
 
-	port = &cxl_root->port;
-	dev = device_find_child(&port->dev, NULL, match_nvdimm_bridge);
-	put_device(&port->dev);
+	dev = device_find_child(&cxl_root->port.dev, NULL, match_nvdimm_bridge);
 
 	if (!dev)
 		return NULL;