'bool is_write' style is obsolete from throttle framework, adapt
fsdev to the new style.

Cc: Greg Kurz <groug@kaod.org>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230728022006.1098509-9-pizhenwei@bytedance.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>