Bluetooth: btmrvl: fix race issue while stopping main thread

btmrvl_remove_card() calls kthread_stop() to stop the main thread,
but kthread_should_stop() is checked when all the activities are done
in the main thread before sleeping.
We will have kthread_should_stop() check as soon as main thread is
woken up. This fixes a crash issue caused due to an invalid memory
access while unnecessarily processing interrupts after card removal.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btmrvl_main.c

@@ -616,6 +616,11 @@ static int btmrvl_service_main_thread(void *data)
 
 		BT_DBG("main_thread woke up");
 
+		if (kthread_should_stop()) {
+			BT_DBG("main_thread: break from main thread");
+			break;
+		}
+
 		spin_lock_irqsave(&priv->driver_lock, flags);
 		if (adapter->int_count) {
 			adapter->int_count = 0;