Add the description to the parameters addr and free_filters
of the function unregister_ftrace_direct().

Link: https://lore.kernel.org/linux-trace-kernel/20240606132520.1397567-1-marilene.agarcia@gmail.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Signed-off-by: Marilene A Garcia <marilene.agarcia@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>