Bug#35710383 mysql server 8.1.0 crashed at GetAccessPathsFromItem

This commit removes a redundant if-test to fix the above bug. For the
failing query, the optimizer short-circuits planning for a subquery in
a projection due to an impossible HAVING condition. This then
triggered the null pointer error.

Change-Id: Id36450f92c872eb520d583d2902dd8d9b7803843

Author: Jan Wedvik

sql/join_optimizer/explain_access_path.cc

@@ -252,9 +252,8 @@ static bool AddSubqueryPaths(const Item *item_arg, const char *source_text,
                "Select #%d (subquery in %s; run only once)",
                query_block->select_number, source_text);
     }
-    if (query_block->join->needs_finalize) {
-      qe->finalize(current_thd);
-    }
+
+    qe->finalize(current_thd);
     AccessPath *path;
     if (qe->root_access_path() != nullptr) {
       path = qe->root_access_path();