xfs: add some more debug checks to buffer log item reuse

Just to make sure the item isn't associated with another
transaction when we try to reuse it.

Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/xfs_buf_item.c

@@ -745,8 +745,10 @@ xfs_buf_item_init(
 	 * nothing to do here so return.
 	 */
 	ASSERT(bp->b_target->bt_mount == mp);
-	if (bip != NULL) {
+	if (bip) {
 		ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
+		ASSERT(!bp->b_transp);
+		ASSERT(bip->bli_buf == bp);
 		return 0;
 	}