Remove rw from {,__,do_}blockdev_direct_IO()

Most filesystems call through to these at some point, so we'll start
here.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index b5e8789..bc23afd 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -152,9 +152,8 @@
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
 
-	return __blockdev_direct_IO(rw, iocb, inode, I_BDEV(inode), iter,
-				    offset, blkdev_get_block,
-				    NULL, NULL, 0);
+	return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter, offset,
+				    blkdev_get_block, NULL, NULL, 0);
 }
 
 int __sync_blockdev(struct block_device *bdev, int wait)