Fix incorrect assertion in heapgettup_pagemode()

Hi,

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 469397e7344..1229e22e78a 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -1077,7 +1077,7 @@ continue_page:
                        ItemId          lpp;
                        OffsetNumber lineoff;
 
-                       Assert(lineindex <= scan->rs_ntuples);
+                       Assert(lineindex < scan->rs_ntuples);
                        lineoff = scan->rs_vistuples[lineindex];
                        lpp = PageGetItemId(page, lineoff);
                        Assert(ItemIdIsNormal(lpp));

The lineindex is 0-based, so it should be '<' rather than '<=', thoughts?

--
Regards,
ChangAo Chen