MDEV-17491 post-fix: GCC 7 -Wclass-memaccess

commit 3a37644 added a non-POD member buf_page_info_t::id, and thus GCC 7 or later would complain about a memset() call. Let my_malloc fill the memory for us.

Author: dr-m

storage/innobase/handler/i_s.cc

@@ -4612,15 +4612,13 @@ static int i_s_innodb_fill_buffer_lru(THD *thd, TABLE_LIST *tables, Item *)
 
 /* Print error message if malloc fail */
 info_buffer = (buf_page_info_t*) my_malloc(PSI_INSTRUMENT_ME,
-lru_len * sizeof *info_buffer, MYF(MY_WME));
+lru_len * sizeof *info_buffer, MYF(MY_WME | MY_ZEROFILL));;
 
 if (!info_buffer) {
 status = 1;
 goto exit;
 }
 
-memset(info_buffer, 0, lru_len * sizeof *info_buffer);
-
 /* Walk through Pool's LRU list and print the buffer page
 information */
 bpage = UT_LIST_GET_LAST(buf_pool.LRU);