[PATCH] Fix bug in xlogitm idbg command

[Lachlan McIlroy]

Print out the correct field for the back pointer in the
xlogitm idbg command.

--- a/fs/xfs/xfsidbg.c	2008-12-04 13:57:45.000000000 +1100
+++ b/fs/xfs/xfsidbg.c	2008-12-03 17:16:55.000000000 +1100
@@ -6373,7 +6250,7 @@ xfsidbg_xlogitem(xfs_log_item_t *lip)
  	printflags((uint)(lip->li_flags), li_flags,"log");
  	kdb_printf("\n");
  	kdb_printf("ail forw 0x%p ail back 0x%p lsn %s\ndesc %p ops 0x%p",
-		lip->li_ail.next, lip->li_ail.next,
+		lip->li_ail.next, lip->li_ail.prev,
  		xfs_fmtlsn(&(lip->li_lsn)), lip->li_desc, lip->li_ops);
  	kdb_printf(" iodonefunc &0x%p\n", lip->li_cb);
  	if (lip->li_type == XFS_LI_BUF) {