md/raid1: minor typos and reformatting.

Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/raid1.c

@@ -901,10 +901,10 @@ static sector_t wait_barrier(struct r1conf *conf, struct bio *bio)
 		 * However if there are already pending
 		 * requests (preventing the barrier from
 		 * rising completely), and the
-		 * pre-process bio queue isn't empty,
+		 * per-process bio queue isn't empty,
 		 * then don't wait, as we need to empty
-		 * that queue to get the nr_pending
-		 * count down.
+		 * that queue to allow conf->start_next_window
+		 * to increase.
 		 */
 		wait_event_lock_irq(conf->wait_barrier,
 				    !conf->array_frozen &&