tracing/user_events: Fix call print_fmt leak

If user_event_trace_register() fails within user_event_parse() the
call's print_fmt member is not freed. Add kfree call to fix this.

Link: https://lkml.kernel.org/r/20221123183248.554-1-beaub@linux.microsoft.com

Fixes: aa3b2b4c ("user_events: Add print_fmt generation support for basic types")
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/trace_events_user.c

@@ -1359,6 +1359,7 @@ static int user_event_parse(struct user_event_group *group, char *name,
 put_user:
 	user_event_destroy_fields(user);
 	user_event_destroy_validators(user);
+	kfree(user->call.print_fmt);
 	kfree(user);
 	return ret;
 }