xfs: remove unused t_callback field in struct xfs_trans

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 5fab0e6..50bd4ac 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -1416,10 +1416,6 @@
 {
 	struct xfs_log_item_desc *lidp, *next;
 
-	/* Call the transaction's completion callback if there is one. */
-	if (tp->t_callback != NULL)
-		tp->t_callback(tp, tp->t_callarg);
-
 	list_for_each_entry_safe(lidp, next, &tp->t_items, lid_trans) {
 		xfs_trans_item_committed(lidp->lid_item, tp->t_lsn, abortflag);
 		xfs_trans_free_item_desc(lidp);
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index e2cbe4d..246286b 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -399,8 +399,6 @@
 						 * transaction. */
 	struct xfs_mount	*t_mountp;	/* ptr to fs mount struct */
 	struct xfs_dquot_acct   *t_dqinfo;	/* acctg info for dquots */
-	xfs_trans_callback_t	t_callback;	/* transaction callback */
-	void			*t_callarg;	/* callback arg */
 	unsigned int		t_flags;	/* misc flags */
 	int64_t			t_icount_delta;	/* superblock icount change */
 	int64_t			t_ifree_delta;	/* superblock ifree change */