direct-io: eliminate the offset argument to ->direct_IO

Including blkdev_direct_IO and dax_do_io.  It has to be ki_pos to actually
work, so eliminate the superflous argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index c03d074..cb070aa 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3854,7 +3854,7 @@
  * Direct IO is not yet supported in the cached mode. 
  */
 static ssize_t
-cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
+cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter)
 {
         /*
          * FIXME