soc/tegra: cbb: Drop unnecessary debugfs error handling

Kernel coding style expects all drivers to ignore debugfs errors.
Partially because it is purely for debugging, not for important user
interfaces.  Simplify the code by dropping unnecessary probe failuring
and error message on debugfs failures, which also fixes incorrect usage
IS_ERR_OR_NULL() and Smatch warning:

  drivers/soc/tegra/cbb/tegra-cbb.c:80 tegra_cbb_err_debugfs_init() warn: passing zero to 'PTR_ERR'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250104141958.115911-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/soc/tegra/cbb/tegra-cbb.c

@@ -69,19 +69,12 @@ static int tegra_cbb_err_show(struct seq_file *file, void *data)
 }
 DEFINE_SHOW_ATTRIBUTE(tegra_cbb_err);
 
-static int tegra_cbb_err_debugfs_init(struct tegra_cbb *cbb)
+static void tegra_cbb_err_debugfs_init(struct tegra_cbb *cbb)
 {
 	static struct dentry *root;
 
-	if (!root) {
+	if (!root)
 		root = debugfs_create_file("tegra_cbb_err", 0444, NULL, cbb, &tegra_cbb_err_fops);
-		if (IS_ERR_OR_NULL(root)) {
-			pr_err("%s(): could not create debugfs node\n", __func__);
-			return PTR_ERR(root);
-		}
-	}
-
-	return 0;
 }
 
 void tegra_cbb_stall_enable(struct tegra_cbb *cbb)
@@ -148,13 +141,8 @@ int tegra_cbb_register(struct tegra_cbb *cbb)
 {
 	int ret;
 
-	if (IS_ENABLED(CONFIG_DEBUG_FS)) {
-		ret = tegra_cbb_err_debugfs_init(cbb);
-		if (ret) {
-			dev_err(cbb->dev, "failed to create debugfs\n");
-			return ret;
-		}
-	}
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		tegra_cbb_err_debugfs_init(cbb);
 
 	/* register interrupt handler for errors due to different initiators */
 	ret = cbb->ops->interrupt_enable(cbb);