Staging: ipack: dereferencing freed memory

We free "dev" then dereference it on the next line.

Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ipack/bridges/tpci200.c

@@ -867,8 +867,8 @@ static int tpci200_slot_unregister(struct ipack_device *dev)
 		return -ERESTARTSYS;
 
 	ipack_device_unregister(dev);
-	kfree(dev);
 	tpci200->slots[dev->slot].dev = NULL;
+	kfree(dev);
 	mutex_unlock(&tpci200->mutex);
 
 	return 0;