fs/afs: use struct_size() in kzalloc()

As Gustavo said in other patches doing the same replace, we can now
use the new struct_size() helper to avoid leaving these open-coded and
prone to type mistake.
Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/dir.c

@@ -242,8 +242,7 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 	if (nr_inline > (PAGE_SIZE - sizeof(*req)) / sizeof(struct page *))
 		nr_inline = 0;
 
-	req = kzalloc(sizeof(*req) + sizeof(struct page *) * nr_inline,
-		      GFP_KERNEL);
+	req = kzalloc(struct_size(req, array, nr_inline), GFP_KERNEL);
 	if (!req)
 		return ERR_PTR(-ENOMEM);
 

fs/afs/file.c

@@ -314,8 +314,7 @@ int afs_page_filler(void *data, struct page *page)
 		/* fall through */
 	default:
 	go_on:
-		req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
-			      GFP_KERNEL);
+		req = kzalloc(struct_size(req, array, 1), GFP_KERNEL);
 		if (!req)
 			goto enomem;
 
@@ -465,8 +464,7 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 		n++;
 	}
 
-	req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *) * n,
-		      GFP_NOFS);
+	req = kzalloc(struct_size(req, array, n), GFP_NOFS);
 	if (!req)
 		return -ENOMEM;
 

fs/afs/write.c

@@ -48,8 +48,7 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
 		return 0;
 	}
 
-	req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
-		      GFP_KERNEL);
+	req = kzalloc(struct_size(req, array, 1), GFP_KERNEL);
 	if (!req)
 		return -ENOMEM;