block: Don't check QUEUE_FLAG_SAME_COMP in __blk_complete_request

In __blk_complete_request, we check both QUEUE_FLAG_SAME_COMP and req->cpu
to decide whether we should use req->cpu. Actually the user can also
select the complete cpu by either setting BIO_CPU_AFFINE or by calling
bio_set_completion_cpu. Current solution makes these 2 ways don't work
any more. So we'd better just check req->cpu.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-softirq.c

@@ -115,7 +115,7 @@ void __blk_complete_request(struct request *req)
 	/*
 	 * Select completion CPU
 	 */
-	if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) && req->cpu != -1) {
+	if (req->cpu != -1) {
 		ccpu = req->cpu;
 		if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) {
 			ccpu = blk_cpu_to_group(ccpu);