switch {__,}blockdev_direct_IO() to iov_iter

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/udf/inode.c

@@ -226,8 +226,7 @@ static ssize_t udf_direct_IO(int rw, struct kiocb *iocb,
 	size_t count = iov_iter_count(iter);
 	ssize_t ret;
 
-	ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset, iter->nr_segs,
-				  udf_get_block);
+	ret = blockdev_direct_IO(rw, iocb, inode, iter, offset, udf_get_block);
 	if (unlikely(ret < 0 && (rw & WRITE)))
 		udf_write_failed(mapping, offset + count);
 	return ret;