switch epoll_wait(2) to fget_light()

SYSCALL_DEFINE4(epoll_wait, int, epfd, struct epoll_event __user *, events,

		int, maxevents, int, timeout)

{

	int error;

	int error, fput_needed;

	struct file *file;

	struct eventpoll *ep;

	/* Get the "struct file *" for the eventpoll file */

	error = -EBADF;

	file = fget(epfd);

	file = fget_light(epfd, &fput_needed);

	if (!file)

		goto error_return;

	error = ep_poll(ep, events, maxevents, timeout);

error_fput:

	fput(file);

	fput_light(file, fput_needed);

error_return:

	return error;