drm/bridge: ti-sn65dsi86: Clean debugfs code

Let's cleanup the debugfs code to:
- Check for errors.
- Use devm to manage freeing, which also means we don't need to store
  a pointer in our structure.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210423095743.v5.5.I5fe072753290c6a77eda736ebd5778e17b7cb0fb@changeid

drivers/gpu/drm/bridge/ti-sn65dsi86.c

@@ -118,7 +118,6 @@
  * @aux:          Our aux channel.
  * @bridge:       Our bridge.
  * @connector:    Our connector.
- * @debugfs:      Used for managing our debugfs.
  * @host_node:    Remote DSI node.
  * @dsi:          Our MIPI DSI source.
  * @edid:         Detected EDID of eDP panel.
@@ -146,7 +145,6 @@ struct ti_sn65dsi86 {
 	struct drm_dp_aux		aux;
 	struct drm_bridge		bridge;
 	struct drm_connector		connector;
-	struct dentry			*debugfs;
 	struct edid			*edid;
 	struct device_node		*host_node;
 	struct mipi_dsi_device		*dsi;
@@ -245,18 +243,31 @@ static int status_show(struct seq_file *s, void *data)
 
 DEFINE_SHOW_ATTRIBUTE(status);
 
-static void ti_sn65dsi86_debugfs_init(struct ti_sn65dsi86 *pdata)
+static void ti_sn65dsi86_debugfs_remove(void *data)
 {
-	pdata->debugfs = debugfs_create_dir(dev_name(pdata->dev), NULL);
-
-	debugfs_create_file("status", 0600, pdata->debugfs, pdata,
-			&status_fops);
+	debugfs_remove_recursive(data);
 }
 
-static void ti_sn65dsi86_debugfs_remove(struct ti_sn65dsi86 *pdata)
+static void ti_sn65dsi86_debugfs_init(struct ti_sn65dsi86 *pdata)
 {
-	debugfs_remove_recursive(pdata->debugfs);
-	pdata->debugfs = NULL;
+	struct device *dev = pdata->dev;
+	struct dentry *debugfs;
+	int ret;
+
+	debugfs = debugfs_create_dir(dev_name(dev), NULL);
+
+	/*
+	 * We might get an error back if debugfs wasn't enabled in the kernel
+	 * so let's just silently return upon failure.
+	 */
+	if (IS_ERR_OR_NULL(debugfs))
+		return;
+
+	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_debugfs_remove, debugfs);
+	if (ret)
+		return;
+
+	debugfs_create_file("status", 0600, debugfs, pdata, &status_fops);
 }
 
 /* Connector funcs */
@@ -1317,8 +1328,6 @@ static int ti_sn65dsi86_remove(struct i2c_client *client)
 
 	kfree(pdata->edid);
 
-	ti_sn65dsi86_debugfs_remove(pdata);
-
 	drm_bridge_remove(&pdata->bridge);
 
 	of_node_put(pdata->host_node);