tracing/dynevent: Fix a memory leak in an error handling path

We must free 'argv' before returning, as already done in all the other
paths of this function.

Link: https://lkml.kernel.org/r/21e3594ccd7fc88c5c162c98450409190f304327.1618136448.git.christophe.jaillet@wanadoo.fr

Fixes: d262271d ("tracing/dynevent: Delegate parsing to create function")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace_dynevent.c

@@ -63,8 +63,10 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type
 		event = p + 1;
 		*p = '\0';
 	}
-	if (event[0] == '\0')
-		return -EINVAL;
+	if (event[0] == '\0') {
+		ret = -EINVAL;
+		goto out;
+	}
 
 	mutex_lock(&event_mutex);
 	for_each_dyn_event_safe(pos, n) {