MDEV-37501 plugins.server_audit Fails in 12.1+

DISCONNECT audit record is added at some point after the actual
disconnect. To have it at the deterministic place in the log,
we have to wait for it to be added before continuing.

Author: vuvova

mysql-test/suite/plugins/r/server_audit.result

@@ -249,6 +249,7 @@ set global server_audit_logging= off;
 set global server_audit_incl_users='root';
 set global server_audit_logging= on;
 disconnect cn1;
+Line count in file: 140
 drop user user1@localhost;
 set global server_audit_events='';
 set global server_audit_incl_users='root, plug_dest, ssl_user1';
@@ -264,6 +265,7 @@ USER()	CURRENT_USER()
 plug@localhost	plug_dest@%
 connection default;
 disconnect plug_con;
+Line count in file: 174
 DROP USER plug;
 DROP USER plug_dest;
 CREATE USER ssl_user1@localhost require SSL;
@@ -273,6 +275,7 @@ select variable_value > '' as 'have_ssl' from information_schema.session_status
 have_ssl
 1
 disconnect conssl1;
+Line count in file: 205
 connection default;
 DROP USER ssl_user1@localhost;
 set global server_audit_query_log_limit= 15;

mysql-test/suite/plugins/t/server_audit.test

@@ -189,6 +189,8 @@ set global server_audit_logging= off;
 set global server_audit_incl_users='root';
 set global server_audit_logging= on;
 disconnect cn1;
+let SEARCH_COUNT= 140;
+source include/wait_for_line_count_in_file.inc;
 
 drop user user1@localhost;
 
@@ -208,6 +210,8 @@ connect(plug_con,localhost,plug,plug_dest,"*NO-ONE*");
 select USER(),CURRENT_USER();
 connection default;
 disconnect plug_con;
+let SEARCH_COUNT= 174;
+source include/wait_for_line_count_in_file.inc;
 DROP USER plug;
 DROP USER plug_dest;
 
@@ -217,6 +221,8 @@ connect (conssl1,localhost,ssl_user1,,sa_db,,,SSL);
 --let $ssl_version = query_get_value(SHOW STATUS LIKE 'Ssl_version', Value, 1)
 select variable_value > '' as 'have_ssl' from information_schema.session_status where variable_name='ssl_cipher';
 disconnect conssl1;
+let SEARCH_COUNT= 205;
+source include/wait_for_line_count_in_file.inc;
 connection default;
 DROP USER ssl_user1@localhost;