block: Fix queue_flag update when rq_affinity goes from 2 to 1

Commit 5757a6d7 added the QUEUE_FLAG_SAME_FORCE flag, but fails to
clear that flag when the current state is '2' (SAME_COMP + SAME_FORCE)
and the new state is '1' (SAME_COMP).
Acked-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Eric Seppanen <eric@purestorage.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

block/blk-sysfs.c

@@ -258,11 +258,13 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
 
 	ret = queue_var_store(&val, page, count);
 	spin_lock_irq(q->queue_lock);
-	if (val) {
+	if (val == 2) {
 		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
-		if (val == 2)
 		queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
-	} else {
+	} else if (val == 1) {
+		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
+		queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
+	} else if (val == 0) {
 		queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
 		queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 	}