btrfs_file_aio_write(): get rid of ppos

static ssize_t __btrfs_direct_write(struct kiocb *iocb,

				    const struct iovec *iov,

				    unsigned long nr_segs, loff_t pos,

				    loff_t *ppos, size_t count, size_t ocount)

				    size_t count, size_t ocount)

{

	struct file *file = iocb->ki_filp;

	struct iov_iter i;

	loff_t endbyte;

	int err;

	written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,

	written = generic_file_direct_write(iocb, iov, &nr_segs, pos, &iocb->ki_pos,

					    count, ocount);

	if (written < 0 || written == count)

	if (err)

		goto out;

	written += written_buffered;

	*ppos = pos + written_buffered;

	iocb->ki_pos = pos + written_buffered;

	invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,

				 endbyte >> PAGE_CACHE_SHIFT);

out:

	struct file *file = iocb->ki_filp;

	struct inode *inode = file_inode(file);

	struct btrfs_root *root = BTRFS_I(inode)->root;

	loff_t *ppos = &iocb->ki_pos;

	u64 start_pos;

	ssize_t num_written = 0;

	ssize_t err = 0;

	if (unlikely(file->f_flags & O_DIRECT)) {

		num_written = __btrfs_direct_write(iocb, iov, nr_segs,

						   pos, ppos, count, ocount);

						   pos, count, ocount);

	} else {

		struct iov_iter i;

		num_written = __btrfs_buffered_write(file, &i, pos);

		if (num_written > 0)

			*ppos = pos + num_written;

			iocb->ki_pos = pos + num_written;

	}

	mutex_unlock(&inode->i_mutex);