drbd: Deletion of an unnecessary check before the function call "lc_destroy"

The lc_destroy() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NRoland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

drivers/block/drbd/drbd_nl.c

@@ -1133,7 +1133,6 @@ static int drbd_check_al_size(struct drbd_device *device, struct disk_conf *dc)
 		lc_destroy(n);
 		return -EBUSY;
 	} else {
-		if (t)
 		lc_destroy(t);
 	}
 	drbd_md_mark_dirty(device); /* we changed device->act_log->nr_elemens */