io_uring: use bvec_set_page to initialize a bvec

Use the bvec_set_page helper to initialize a bvec.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230203150634.3199647-19-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/rsrc.c

@@ -1237,9 +1237,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
 		size_t vec_len;
 
 		vec_len = min_t(size_t, size, PAGE_SIZE - off);
-		imu->bvec[i].bv_page = pages[i];
-		imu->bvec[i].bv_len = vec_len;
-		imu->bvec[i].bv_offset = off;
+		bvec_set_page(&imu->bvec[i], pages[i], vec_len, off);
 		off = 0;
 		size -= vec_len;
 	}