MDEV-16125 Shutdown crash when innodb_force_recovery >= 2

Problem:
=======
InnoDB master thread encounters the shutdown state as SRV_SHUTDOWN_FLUSH_PHASE
when innodb_force_recovery >=2 and slow scheduling of master thread during
shutdown.

Fix:
====
There is no need for master thread itself if innodb_force_recovery >=2.
Don't create the master thread if innodb_force_recovery >= 2

storage/innobase/srv/srv0srv.cc

@@ -2447,10 +2447,6 @@ DECLARE_THREAD(srv_master_thread)(
 	ut_a(slot == srv_sys.sys_threads);
 
 loop:
-	if (srv_force_recovery >= SRV_FORCE_NO_BACKGROUND) {
-		goto suspend_thread;
-	}
-
 	while (srv_shutdown_state == SRV_SHUTDOWN_NONE) {
 
 		srv_master_sleep();
@@ -2465,7 +2461,6 @@ DECLARE_THREAD(srv_master_thread)(
 		}
 	}
 
-suspend_thread:
 	switch (srv_shutdown_state) {
 	case SRV_SHUTDOWN_NONE:
 		break;

storage/innobase/srv/srv0start.cc

@@ -2642,7 +2642,8 @@ innobase_start_or_create_for_mysql()
 	/* Create the master thread which does purge and other utility
 	operations */
 
-	if (!srv_read_only_mode) {
+	if (!srv_read_only_mode
+	    && srv_force_recovery < SRV_FORCE_NO_BACKGROUND) {
 		thread_handles[1 + SRV_MAX_N_IO_THREADS] = os_thread_create(
 			srv_master_thread,
 			NULL, thread_ids + (1 + SRV_MAX_N_IO_THREADS));