block: remove IOPRIO_BITS

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

include/linux/ioprio.h

@@ -7,7 +7,6 @@
 /*
  * Gives us 8 prio classes with 13-bits of data for each class
  */
-#define IOPRIO_BITS		(16)
 #define IOPRIO_CLASS_SHIFT	(13)
 #define IOPRIO_PRIO_MASK	((1UL << IOPRIO_CLASS_SHIFT) - 1)