btrfs: zoned: fix comment description for sb_write_pointer logic

Fix the comment to represent the actual logic used for sb_write_pointer

- Empty[0] && In use[1] should be an invalid state instead of returning
  zone 0 wp
- Empty[0] && Full[1] should be returning zone 0 wp instead of zone 1 wp
- In use[0] && Empty[1] should be returning zone 0 wp instead of being an
  invalid state
- In use[0] && Full[1] should be returning zone 0 wp instead of returning
  zone 1 wp
- Full[0] && Empty[1] should be returning zone 1 wp instead of returning
  zone 0 wp
- Full[0] && In use[1] should be returning zone 1 wp instead of returning
  zone 0 wp
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NPankaj Raghav <p.raghav@samsung.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/zoned.c

@@ -94,9 +94,9 @@ static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
 	 * Possible states of log buffer zones
 	 *
 	 *           Empty[0]  In use[0]  Full[0]
-	 * Empty[1]         *          x        0
-	 * In use[1]        0          x        0
-	 * Full[1]          1          1        C
+	 * Empty[1]         *          0        1
+	 * In use[1]        x          x        1
+	 * Full[1]          0          0        C
 	 *
 	 * Log position:
 	 *   *: Special case, no superblock is written