block: Use a folio in blkdev_write_end()

Replaces two hidden calls to compound_head() with one explicit one.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

block/fops.c

@@ -460,11 +460,12 @@ static int blkdev_write_end(struct file *file, struct address_space *mapping,
 		loff_t pos, unsigned len, unsigned copied, struct page *page,
 		void *fsdata)
 {
+	struct folio *folio = page_folio(page);
 	int ret;
 	ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
 
-	unlock_page(page);
-	put_page(page);
+	folio_unlock(folio);
+	folio_put(folio);
 
 	return ret;
 }