io_uring: clean io_prep_rw()

We already store req->file in a variable in io_prep_rw(), just use it
instead of a couple of left references to kicob->ki_filp.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2f5889fc7ab670daefd5ccaedd99416d8355f0ad.1634314022.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -2832,8 +2832,8 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		req->flags |= REQ_F_CUR_POS;
 		kiocb->ki_pos = file->f_pos;
 	}
-	kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
-	kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
+	kiocb->ki_hint = ki_hint_validate(file_write_hint(file));
+	kiocb->ki_flags = iocb_flags(file);
 	ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
 	if (unlikely(ret))
 		return ret;
@@ -2858,8 +2858,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		kiocb->ki_ioprio = get_current_ioprio();
 
 	if (ctx->flags & IORING_SETUP_IOPOLL) {
-		if (!(kiocb->ki_flags & IOCB_DIRECT) ||
-		    !kiocb->ki_filp->f_op->iopoll)
+		if (!(kiocb->ki_flags & IOCB_DIRECT) || !file->f_op->iopoll)
 			return -EOPNOTSUPP;
 
 		kiocb->ki_flags |= IOCB_HIPRI | IOCB_ALLOC_CACHE;