ubi: fastmap: Use the bitmap API to allocate bitmaps

Use bitmap_zalloc()/bitmap_free() instead of hand-writing them.

It is less verbose and it improves the semantic.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

drivers/mtd/ubi/fastmap.c

@@ -20,8 +20,7 @@ static inline unsigned long *init_seen(struct ubi_device *ubi)
 	if (!ubi_dbg_chk_fastmap(ubi))
 		return NULL;
 
-	ret = kcalloc(BITS_TO_LONGS(ubi->peb_count), sizeof(unsigned long),
-		      GFP_KERNEL);
+	ret = bitmap_zalloc(ubi->peb_count, GFP_KERNEL);
 	if (!ret)
 		return ERR_PTR(-ENOMEM);
 
@@ -34,7 +33,7 @@ static inline unsigned long *init_seen(struct ubi_device *ubi)
  */
 static inline void free_seen(unsigned long *seen)
 {
-	kfree(seen);
+	bitmap_free(seen);
 }
 
 /**
@@ -1108,8 +1107,7 @@ int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
 	if (!ubi->fast_attach)
 		return 0;
 
-	vol->checkmap = kcalloc(BITS_TO_LONGS(leb_count), sizeof(unsigned long),
-				GFP_KERNEL);
+	vol->checkmap = bitmap_zalloc(leb_count, GFP_KERNEL);
 	if (!vol->checkmap)
 		return -ENOMEM;
 
@@ -1118,7 +1116,7 @@ int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
 
 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
 {
-	kfree(vol->checkmap);
+	bitmap_free(vol->checkmap);
 }
 
 /**