MDEV-5321 Calling mysql_library_end accesses freed memory; dumps memory to display.

        Don't call the vio_end() in the clean_up() in EMBEDDED mode.
        Call vio_end() before the end_embedded_server().

libmysql/libmysql.c

@@ -204,11 +204,11 @@ void STDCALL mysql_server_end()
 
   mysql_client_plugin_deinit();
 
+  finish_client_errs();
+  vio_end();
 #ifdef EMBEDDED_LIBRARY
   end_embedded_server();
 #endif
-  finish_client_errs();
-  vio_end();
 
   /* If library called my_init(), free memory allocated by it */
   if (!org_my_init_done)

sql/mysqld.cc

@@ -1851,7 +1851,9 @@ void clean_up(bool print_message)
   delete binlog_filter;
   delete rpl_filter;
   end_ssl();
+#ifndef EMBEDDED_LIBRARY
   vio_end();
+#endif /*!EMBEDDED_LIBRARY*/
   my_regex_end();
 #if defined(ENABLED_DEBUG_SYNC)
   /* End the debug sync facility. See debug_sync.cc. */