ASoC: SOF: Fix memory leak in sof_dfsentry_write

In the implementation of sof_dfsentry_write() memory allocated for
string is leaked in case of an error. Go to error handling path if the
d_name.name is not valid.

Fixes: 091c12e1 ("ASoC: SOF: debug: add new debugfs entries for IPC flood test")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Link: https://lore.kernel.org/r/20191027194856.4056-1-navid.emamdoost@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/debug.c

@@ -152,8 +152,10 @@ static ssize_t sof_dfsentry_write(struct file *file, const char __user *buffer,
 	 */
 	dentry = file->f_path.dentry;
 	if (strcmp(dentry->d_name.name, "ipc_flood_count") &&
-	    strcmp(dentry->d_name.name, "ipc_flood_duration_ms"))
-		return -EINVAL;
+	    strcmp(dentry->d_name.name, "ipc_flood_duration_ms")) {
+		ret = -EINVAL;
+		goto out;
+	}
 
 	if (!strcmp(dentry->d_name.name, "ipc_flood_duration_ms"))
 		flood_duration_test = true;