direct_IO: remove rw from a_ops->direct_IO()

Now that no one is using rw, remove it completely.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
index e7047b6..070dc4b 100644
--- a/fs/jfs/inode.c
+++ b/fs/jfs/inode.c
@@ -330,8 +330,8 @@
 	return generic_block_bmap(mapping, block, jfs_get_block);
 }
 
-static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
-	struct iov_iter *iter, loff_t offset)
+static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
+			     loff_t offset)
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;