block: partition: introduce hd_free_part()

So the helper can be used in both generic partition
case and part0 case.
Signed-off-by: NMing Lei <tom.leiming@gmail.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

block/genhd.c

@@ -1110,8 +1110,7 @@ static void disk_release(struct device *dev)
 	disk_release_events(disk);
 	kfree(disk->random);
 	disk_replace_part_tbl(disk, NULL);
-	free_part_stats(&disk->part0);
-	free_part_info(&disk->part0);
+	hd_free_part(&disk->part0);
 	if (disk->queue)
 		blk_put_queue(disk->queue);
 	kfree(disk);

block/partition-generic.c

@@ -212,8 +212,7 @@ static void part_release(struct device *dev)
 {
 	struct hd_struct *p = dev_to_part(dev);
 	blk_free_devt(dev->devt);
-	free_part_stats(p);
-	free_part_info(p);
+	hd_free_part(p);
 	kfree(p);
 }
 

include/linux/genhd.h

@@ -663,6 +663,12 @@ static inline void hd_struct_put(struct hd_struct *part)
 		__delete_partition(part);
 }
 
+static inline void hd_free_part(struct hd_struct *part)
+{
+	free_part_stats(part);
+	free_part_info(part);
+}
+
 /*
  * Any access of part->nr_sects which is not protected by partition
  * bd_mutex or gendisk bdev bd_mutex, should be done using this