null_blk: use available 'dev' in nullb_device_power_store()

We already have this pointer, no need to use to_nullb_device()
again.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 3b5cabe..bd92286 100644 (file)
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -375,7 +375,7 @@ static ssize_t nullb_device_power_store(struct config_item *item,
 
                set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags);
                dev->power = newp;
-       } else if (to_nullb_device(item)->power && !newp) {
+       } else if (dev->power && !newp) {
                mutex_lock(&lock);
                dev->power = newp;
                null_del_dev(dev->nullb);