block: add debugfs stanza for QUEUE_FLAG_NOWAIT

This was missed in 021a2446. Leads to the numeric value of
QUEUE_FLAG_NOWAIT (i.e. 29) showing up in
/sys/kernel/debug/block/*/state.

Fixes: 021a2446
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq-debugfs.c

@@ -129,6 +129,7 @@ static const char *const blk_queue_flag_name[] = {
 	QUEUE_FLAG_NAME(PCI_P2PDMA),
 	QUEUE_FLAG_NAME(ZONE_RESETALL),
 	QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
+	QUEUE_FLAG_NAME(NOWAIT),
 };
 #undef QUEUE_FLAG_NAME