nilfs2: fix using of PageLocked() in nilfs_clear_dirty_page()

Change test_bit(PG_locked, &page->flags) to PageLocked().
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nilfs2/page.c

@@ -407,7 +407,7 @@ void nilfs_clear_dirty_page(struct page *page, bool silent)
 	struct inode *inode = page->mapping->host;
 	struct super_block *sb = inode->i_sb;
 
-	BUG_ON(!test_bit(PG_locked, &page->flags));
+	BUG_ON(!PageLocked(page));
 
 	if (!silent) {
 		nilfs_warning(sb, __func__,