staging: gdm72xx: fix interruptible_sleep_on race

interruptible_sleep_on is racy and going away. This replaces the
use in the gdm72xx driver with the appropriate
wait_event_interruptible_lock_irq.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: devel@driverdev.osuosl.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gdm72xx/gdm_usb.c

@@ -780,9 +780,10 @@ static int k_mode_thread(void *arg)
 
 			spin_lock_irqsave(&k_lock, flags2);
 		}
+		wait_event_interruptible_lock_irq(k_wait,
+						  !list_empty(&k_list) || k_mode_stop,
+						  k_lock);
 		spin_unlock_irqrestore(&k_lock, flags2);
-
-		interruptible_sleep_on(&k_wait);
 	}
 	return 0;
 }