crypto: hash - Use nth_page instead of doing it by hand

Use nth_page instead of adding n to the page pointer.

Signed-off-by: Herbert Xu <[email protected]>

Author: herbertx

crypto/ahash.c

@@ -80,7 +80,7 @@ static int hash_walk_new_entry(struct crypto_hash_walk *walk)
 
 	sg = walk->sg;
 	walk->offset = sg->offset;
-	walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
+	walk->pg = nth_page(sg_page(walk->sg), (walk->offset >> PAGE_SHIFT));
 	walk->offset = offset_in_page(walk->offset);
 	walk->entrylen = sg->length;
 
@@ -221,7 +221,7 @@ int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 	if (!IS_ENABLED(CONFIG_HIGHMEM))
 		return crypto_shash_digest(desc, data, nbytes, req->result);
 
-	page += offset >> PAGE_SHIFT;
+	page = nth_page(page, offset >> PAGE_SHIFT);
 	offset = offset_in_page(offset);
 
 	if (nbytes > (unsigned int)PAGE_SIZE - offset)