A cleanup for MDEV-25243 ASAN heap-use-after-free in...

A cleanup for MDEV-25243 ASAN heap-use-after-free in Item_func_sp::execute_impl upon concurrent view DDL and I_S query with view and function

The test was reported to fail sporadicaly with this diff:

--- mysql-test/main/information_schema_tables.result
+++ mysql-test/main/information_schema_tables.reject
@@ -21,6 +21,8 @@
 disconnect con1;
 connection default;
 DROP VIEW IF EXISTS vv;
+Warnings:
+Note	4092	Unknown VIEW: 'test.vv'

in the "The originally reported non-deterministic test" part.
Disabling warnings around the DROP VIEW statement.

mysql-test/main/information_schema_tables.test

@@ -37,7 +37,9 @@ SELECT v.* FROM v JOIN INFORMATION_SCHEMA.TABLES WHERE DATA_LENGTH = -1;
 --eval KILL $conid
 --disconnect con1
 --connection default
+--disable_warnings
 DROP VIEW IF EXISTS vv;
+--enable_warnings
 DROP VIEW v;
 DROP FUNCTION f;
 DROP TABLE t;