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>

fs/hfsplus/inode.c

@@ -131,8 +131,7 @@ static ssize_t hfsplus_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, offset, 
-				 hfsplus_get_block);
+	ret = blockdev_direct_IO(iocb, inode, iter, offset, hfsplus_get_block);
 
 	/*
 	 * In case of error extending write may have instantiated a few