block: remove the checking for NULL queue in blk_put_request

Some uses blk_put_request asymmetrically, that is, they uses it with
requests that not allocated by blk_get_request. As a result,
blk_put_request has a hack to catch a NULL request_queue. Now such
callers are fixed (they use blk_get_request properly). So we can
safely remove the hack in blk_put_request.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

block/blk-core.c

@@ -1042,15 +1042,9 @@ void blk_put_request(struct request *req)
 	unsigned long flags;
 	struct request_queue *q = req->q;
 
-	/*
-	 * Gee, IDE calls in w/ NULL q.  Fix IDE and remove the
-	 * following if (q) test.
-	 */
-	if (q) {
-		spin_lock_irqsave(q->queue_lock, flags);
-		__blk_put_request(q, req);
-		spin_unlock_irqrestore(q->queue_lock, flags);
-	}
+	spin_lock_irqsave(q->queue_lock, flags);
+	__blk_put_request(q, req);
+	spin_unlock_irqrestore(q->queue_lock, flags);
 }
 EXPORT_SYMBOL(blk_put_request);