md/raid1: Fix a warning message in remove_wb()

The WARN_ON() macro doesn't take an error message, it just takes a
condition.  I've changed this to use WARN(1, "...") instead.

Fixes: 3e148a32 ("md/raid1: fix potential data inconsistency issue with write behind device")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NSong Liu <songliubraving@fb.com>

drivers/md/raid1.c

@@ -96,7 +96,7 @@ static void remove_wb(struct md_rdev *rdev, sector_t lo, sector_t hi)
 		}
 
 	if (!found)
-		WARN_ON("The write behind IO is not recorded\n");
+		WARN(1, "The write behind IO is not recorded\n");
 	spin_unlock_irqrestore(&rdev->wb_list_lock, flags);
 	wake_up(&rdev->wb_io_wait);
 }