ide-cd: fix REQ_QUIET tests in cdrom_decode_status

Original patch (dfa4411cc3a690011cab90e9a536938795366cf9) was buggy.
This is a more proper fix which introduces blk_rq_quiet() macro
alleviating the need for dumb, too short caching variables.

Thanks to Helge Deller and Bart for debugging this.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Reported-and-tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ba54c83..6f841fb 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -598,6 +598,7 @@
 				 blk_failfast_transport(rq) ||	\
 				 blk_failfast_driver(rq))
 #define blk_rq_started(rq)	((rq)->cmd_flags & REQ_STARTED)
+#define blk_rq_quiet(rq)	((rq)->cmd_flags & REQ_QUIET)
 
 #define blk_account_rq(rq)	(blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq)))