pass iov_iter to ->direct_IO()

unmodified, for now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 9e2fecd..09cff13 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -125,15 +125,15 @@
 }
 
 static ssize_t hfs_direct_IO(int rw, struct kiocb *iocb,
-		const struct iovec *iov, loff_t offset, unsigned long nr_segs)
+		struct iov_iter *iter, loff_t offset)
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
 	struct inode *inode = file_inode(file)->i_mapping->host;
 	ssize_t ret;
 
-	ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
-				 hfs_get_block);
+	ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset,
+				 iter->nr_segs, hfs_get_block);
 
 	/*
 	 * In case of error extending write may have instantiated a few
@@ -141,7 +141,7 @@
 	 */
 	if (unlikely((rw & WRITE) && ret < 0)) {
 		loff_t isize = i_size_read(inode);
-		loff_t end = offset + iov_length(iov, nr_segs);
+		loff_t end = offset + iov_length(iter->iov, iter->nr_segs);
 
 		if (end > isize)
 			hfs_write_failed(mapping, end);