Fixes a problem with heap when scanning and insert rows at the same time

This causes failures in versioning.update-big in 10.3 and above

storage/heap/hp_scan.c

@@ -44,6 +44,12 @@ int heap_scan(register HP_INFO *info, uchar *record)
   DBUG_ENTER("heap_scan");
 
   pos= ++info->current_record;
+  if (pos >= share->records+share->deleted)
+  {
+    info->update= 0;                        /* No active row */
+    DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
+  }
+
   if (pos < info->next_block)
   {
     info->current_ptr+=share->block.recbuffer;
@@ -51,15 +57,6 @@ int heap_scan(register HP_INFO *info, uchar *record)
   else
   {
     info->next_block+=share->block.records_in_block;
-    if (info->next_block >= share->records+share->deleted)
-    {
-      info->next_block= share->records+share->deleted;
-      if (pos >= info->next_block)
-      {
-	info->update= 0;
-	DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
-      }
-    }
     hp_find_record(info, pos);
   }
   if (!info->current_ptr[share->visible])