ipmi: fix initialization when workqueue allocation fails

If the workqueue allocation fails, the driver is marked as not initialized,
and timer and panic_notifier will be left registered.

Instead of removing those when workqueue allocation fails, do the workqueue
initialization before doing it, and cleanup srcu_struct if it fails.

Fixes: 1d49eb91 ("ipmi: Move remove_work to dedicated workqueue")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Corey Minyard <cminyard@mvista.com>
Cc: Ioanna Alifieraki <ioanna-maria.alifieraki@canonical.com>
Cc: stable@vger.kernel.org
Message-Id: <20211217154410.1228673-2-cascardo@canonical.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

drivers/char/ipmi/ipmi_msghandler.c

@@ -5396,20 +5396,23 @@ static int ipmi_init_msghandler(void)
 	if (rv)
 		goto out;
 
-	timer_setup(&ipmi_timer, ipmi_timeout, 0);
-	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
-
-	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
-
 	remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq");
 	if (!remove_work_wq) {
 		pr_err("unable to create ipmi-msghandler-remove-wq workqueue");
 		rv = -ENOMEM;
-		goto out;
+		goto out_wq;
 	}
 
+	timer_setup(&ipmi_timer, ipmi_timeout, 0);
+	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
+
+	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
+
 	initialized = true;
 
+out_wq:
+	if (rv)
+		cleanup_srcu_struct(&ipmi_interfaces_srcu);
 out:
 	mutex_unlock(&ipmi_interfaces_mutex);
 	return rv;