nilfs2: use list_first_entry

This uses list_first_entry macro instead of list_entry if it's used to
get the first entry.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/segment.c

@@ -957,8 +957,8 @@ static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
 
  dispose_buffers:
 	while (!list_empty(listp)) {
-		bh = list_entry(listp->next, struct buffer_head,
-				b_assoc_buffers);
+		bh = list_first_entry(listp, struct buffer_head,
+				      b_assoc_buffers);
 		list_del_init(&bh->b_assoc_buffers);
 		brelse(bh);
 	}