Btrfs: remove no longer used io_err from btrfs_log_ctx

	up_write(&BTRFS_I(inode)->dio_sem);

	inode_unlock(inode);

	/*

	 * If any of the ordered extents had an error, just return it to user

	 * space, so that the application knows some writes didn't succeed and

	 * can take proper action (retry for e.g.). Blindly committing the

	 * transaction in this case, would fool userspace that everything was

	 * successful. And we also want to make sure our log doesn't contain

	 * file extent items pointing to extents that weren't fully written to -

	 * just like in the non fast fsync path, where we check for the ordered

	 * operation's error flag before writing to the log tree and return -EIO

	 * if any of them had this flag set (btrfs_wait_ordered_range) -

	 * therefore we need to check for errors in the ordered operations,

	 * which are indicated by ctx.io_err.

	 */

	if (ctx.io_err) {

		btrfs_end_transaction(trans);

		ret = ctx.io_err;

		goto out;

	}

	if (ret != BTRFS_NO_LOG_SYNC) {

		if (!ret) {

			ret = btrfs_sync_log(trans, root, &ctx);

struct btrfs_log_ctx {

	int log_ret;

	int log_transid;

	int io_err;

	bool log_new_dentries;

	struct inode *inode;

	struct list_head list;

{

	ctx->log_ret = 0;

	ctx->log_transid = 0;

	ctx->io_err = 0;

	ctx->log_new_dentries = false;

	ctx->inode = inode;

	INIT_LIST_HEAD(&ctx->list);